egr system on toyota
Joe
me problems, the check engine light is on and shows the egr valve
components. right off the bat i thought it was the egr valve so i went
out and bought one and installed it on the car, it seemed like my
problem was taken care of for a few days then it started acting up
again, its like it has no power until about at 4000 rpms, then it
suddenly gets a boost of power. If there is any advice on what i can
do I sure would appreciate it.
Thanks
Joe
Ray O
"Joe" <steelh...@hotmail.com> wrote in message
news:550ce1d6-b5fb-4f24...@o7g2000yqb.googlegroups.com...
What was the actual trouble code? Has the check engine light come back on?
No power at low RPM or rough idle could be an indication that the EGR valve
is opening or stuck open. Those symptoms could also be caused by a vacuum
leak, bad vacuum switching valve, or bad EGR modulator.
--
Ray O
(correct punctuation to reply)
Mike
the actual cause of your problem and the right people to correct the fault
rather the throwing away money on guessing what is at fault, WBMA
"Joe" <steelh...@hotmail.com> wrote in message
news:550ce1d6-b5fb-4f24...@o7g2000yqb.googlegroups.com...
Hachiroku ハチロク
WOW! I wish I had that much money!!!
I had a '95 Tercel, throwing code P420, IIRC...Low Vacuum, EGR valve.
Basically, the same car as yours.
Took it to a friend with a garage and they read the code.
This code could be
Low vacuum
Bad EGR
Bad O2 sensor
Bad vacuum sensor
I was working at a CarQuest so I bought an O2 sensor. The front sensor
checked good, so we just replaced the downstrem sensor behind the cat.
$60 down the drain. Still throwing codes.
I took it to the 'family' Toyota dealer. They charged me $45 to tell me
the EGR was good (they only charged me time, it's usually $65-80 to check
the EGR). Nope.
After two years, I took the hoses off and replaced them one by one. The
last hose I replaced did the trick.
If I had done some better troubleshooting, it would have only cost me $15
to solve the problem.
I doubt you can return the EGR...
Joe
wrote:
> "Joe" <steelhors...@hotmail.com> wrote in message
It was indicating the trouble code P0401. It was showing insufficient
egr flow. The check engine light is still on, and will always come
back on after resetting the system. My car is also showing a 02-sensor
code for upstream, and at one time it was also showing an Insufficient
Coolant Temperature for Closed Loop Fuel Control. I really did not
bother checking that code, because the code quickly went away. I have
made a test on my modulator by plugging the P and R valve off with my
fingers, and blowing into the Q port. The first time I did it I
couldn’t blow any air through it what so ever. The second time I done
it I was able to blow a little bit through it, then it was like it
stopped up again.
Ray O
*************
Insufficient coolant temperature for closed loop fuel control is kind of a
misnomer - it can be caused by an exhaust leak.
Possible causes for P0401 are:
EGR valve stuck closed
Open or short in VSV circuit
Vacuum or EGR hose disconnected
MAP sensor
EGR VSV open or close malfunction
ECM
To check the EGR modulator:
With the modulator installed on the engine, disconnect vacuum hoses from p
and r and disconnect q from the EGR valve. Plug p and r with your fingers
and blow into q. Air should flow from the air filter side freely.
Start the engine, and maintain 2,500 RPM. Repeat the above test. There
should be a strong resistance to air flow.
From what you described, the modulator may be bad so it would be a good idea
to recheck it.
Joe
I rechecked my modulator on the car; I plugged P and R with my
fingers, and tried to blow into Q. The same result happened again, the
first time the air would go through okay, the second time it would not
go through at all. So I started the car had a buddy hold the
accelerator down to 2500 rpms, and tried it again I could not get no
air through at all. I took all of my vacuum lines off one at a time,
and checked to see if any of them had holes, cracks, or any thing that
would lose vacuum. They all were still in good condition. One more
question could a 02-sensor possibly have anything to do with the
problem Im having. I would just go ahead and take the car to a dealer
and have them diagnose the problem, but I live about 75 miles away
from the closest one. I do not want to drive the car anymore than I
have to, because of the way its running.
Thanks
Joe
Ray O
********
It sounds like your modulator is bad or the filter is clogged since you are
not getting consistent results with the engine off. If you remove and plug
the 3 vacuum lines from the modulator, does the engine run OK? If it does
The best way to check for a vacuum leak is with a vacuum gauge. It should
read over 14 in Hg at idle. The problem with a visual check for vacuum leaks
is that a crack in a vacuum hose fitting is not always visible.
A bad O2 sensor by itself is not likely to cause a rough idle.
Besides an EGR valve opening at idle, other possible causes of a rough idle
are a gummed up idle air control valve, vacuum leak, hole in the intake tube
between the air filter housing and throttle body, dirty MAF sensor,
incorrect ignition timing, incorrect valve timing, clogged air filter, bad
spark plug(s)
Joe
Thanks for all of your help. I will give these things a try out, and
let you know how it goes. If you have any more advice or anything just
let me know.
>Joe
Ray O
You're welcome! Let us know what you find.
Ray O
You're welcome! Let us know what you find.
Joe
Today I went out to Advance Auto Parts and had them hook their
computer up to my car. This time the only codes that were showing were
a P0135 and a P0125. I needed to tell you that a while back I changed
my 02 sensor, when I had it checked the first time. Instead of buying
a Toyota part like I should have, I got a universal 02 sensor. I had
to call AAP to get instructions on how to hook it up. Even after I
hooked it up the way they told me to, it was still throwing the same
code for the 02 sensor. After a while of driving the car I figured I’d
call AAP back and see if they would tell me the same way again of how
to hook it up. This time they told me a completely different way of
how to hook it up. So on that problem I’m completely lost, and have no
idea which way is right. I also rechecked the modulator today, and the
air seemed to go through it just fine. Do you have any ideas now, on
what my possible problem is, I mean the car is running rough at idle,
and also at cruising speed.
Thanks
Joe
Ray O
********
As I mentioned before, P0125 - insufficient coolant temp for closed loop
operation - could be caused by an exhaust leak. I suppose that it could
also be caused by the incorrect O2 sensor.
P0135 - O2 Sensor Heater Circuit Malfunction (Bank 1 Sensor 1) - means what
it says. If you had to splice wires on the universal O2 sensor, check your
splices, preferably with an ohm meter. On a sensor with 4 wires, 2 are for
the sensor heater and 2 are for the sensor signal. You will need an
electrical wiring diagram to determine which wires are which.
If the car runs rough at idle and at cruising speed, check the black plastic
tube between the air filter housing and throttle body for cracks, check the
MAF sensor to make sure the wire isn't fouled, and try a container of
Chevron Techron fuel injector cleaner.
How many miles are on the car? Have the oil changes been done pretty much
on time?
Joe
I was wondering if you might know what the 02 sensor wires mean on my
car. I have a black, light brown, black with a red stripe, and a white
with a blue stripe. I also was going to tell you that when I drove the
car today, when we came to a stop I smelled exhaust real bad. I
checked the muffler system for holes, but did not find any. I’m gonna
check the air filter housing and tube, and put some fuel injector
cleaner in it, to see what that does for it.
Thanks
Joe
Ray O
**********
Unfortunately, I do not have a wiring diagram for your car so I can't help
you with the sensor wire colors. One of the wires should have continuity
with ground and the other three are connected to the ECU. I only use OEM
sensors so I do not have any experience with aftermarket ones.
The exhaust leak is probably the cause of the P0125. If you have trouble
finding the leak, have someone try to plug the tailpipe with the engine
idling - the exhaust noise from the leak should get louder.
mrsteveo
You can add cracked fuel injector to your list too.
Joe
If I had a cracked fuel injector would that make the car run rough at
idle, and also at cruising speed. What kind of sound would it make?
Would a fuel filter also have anything to do with my problem.
Joe
Ray O
<snipped>
> You can add cracked fuel injector to your list too.
If I had a cracked fuel injector would that make the car run rough at
idle, and also at cruising speed. What kind of sound would it make?
Would a fuel filter also have anything to do with my problem.
Joe
********
A cracked fuel injector doesn't make a sound that is different from normal.
Cracked injectors are pretty rare but can be caused by over-use of fuel
injector cleaners and aftermarket fuel additives. If you have not been
adding anything to the fuel tank, a cracked injector is pretty low on the
list.
A fuel filter is also unlikely to have anything to do with your problem
unless you buy really cheap fuel from stations that do not sell a large
volume of fuel.
How many miles are on the car, and what is the recent maintenance history?
When is the last time the spark plugs and ignition wires were replaced? If
they were replaced, what brand was used?
Joe
wrote:
> "Joe" <steelhors...@hotmail.com> wrote in message
The car has about 155,000 miles on it, ever since I got the car I
keep my oil changed every 3000 miles. The spark plugs were replaced
about 10 months ago, but I did not change any wires to them. I used
Bosch double tip platinum, the under the hood diagram said that only
double tip plugs should be used.
Joe
Ray O
Joe
***********
check the resistance on the spark plug wires. If the car has a distributor,
check the condition of the cap and rotor.
Joe
I never have really checked any kind of resistance on spark plug
wires. How do I go about doing this?
Joe
john
car's ECU is NOT going into closed loop operation. During this period
you'll likely have increased emissions that's damaging the oxygen
sensors and catalytic converter. And if the mixture is running too
rich, you can have a lot of carbon plugging things up too (maybe like
EGR valve, throttle body ports, etc).
So I think you should:
1. Sign on to Autozone's free repair guide.
http://www.autozone.com/autozone/
2. Test and/or replace engine coolant temperature sensor.
May look like: http://www.rockauto.com/catalog/moreinfo.php?pk=482090
Check proper part number. About $31+shipping.
3. If you have more than 100K miles on the sensors, consider replacing
them. Since sensors can be damaged by an out-of-tune engine, it helps
to make sure the engine is properly maintained.
4. Then go through the EGR system and clean out all the pipes and
ports. And then go through the standard diagnostics procedure before
buy any more new parts. I think you'll need a good throttle body
cleaning as well from your description of plugged ports.
Ray O
Joe
**************
Disconnect the spark plug wires one at a time from the spark plug and
distributor cap or coil for distributor-less ignition systems and with an
ohm meter, touch the meter's probes to the ends of the spark plug wires (it
doesn't matter which probe lead connects to which end of the wire). With
the ohm meter's range set to K ohms (kilo ohms), the wire's resistance
should be less than 25 K ohms (25,000 ohms). If resistance is greater than
25 K ohms, the wire is bad. Do this for all 4 spark plug wires. If the
wires need replacement, try to use Denso wires.
Ray O
"john" <john...@hotmail.com> wrote in message
news:5e503886-0b50-451c...@y10g2000prf.googlegroups.com...
If you're getting the Insufficient Coolant Temperature code then your
car's ECU is NOT going into closed loop operation. During this period
you'll likely have increased emissions that's damaging the oxygen
sensors and catalytic converter. And if the mixture is running too
rich, you can have a lot of carbon plugging things up too (maybe like
EGR valve, throttle body ports, etc).
So I think you should:
1. Sign on to Autozone's free repair guide.
http://www.autozone.com/autozone/
**********
I like Autozone's repair guides but unfortunately, the OP's Paseo is not one
with an available repair guide, and neither is the same model year Tercel.
*********
2. Test and/or replace engine coolant temperature sensor.
May look like: http://www.rockauto.com/catalog/moreinfo.php?pk=482090
Check proper part number. About $31+shipping.
**********
The engine coolant temp sensor does not affect P0125. The ECU detects P0125
by lookinng at O2 sensor voltage that is out of range, either from an open
or short in the sensor circuit, or an exhaust leak that is introducing air
to the exhaust stream, making the system think that it is running too lean.
Since the OP mentioned an exhaust smell in the car, I think the OP should
check for an exhaust leak.
**********
3. If you have more than 100K miles on the sensors, consider replacing
them. Since sensors can be damaged by an out-of-tune engine, it helps
to make sure the engine is properly maintained.
*********
The OP replaced a sensor with an aftermarket one and now has a problem with
that sensor.
*********
Joe
wrote:
> "john" <johngd...@hotmail.com> wrote in message
>
> news:5e503886-0b50-451c...@y10g2000prf.googlegroups.com...
> If you're getting the Insufficient Coolant Temperature code then your
> car's ECU is NOT going into closed loop operation. During this period
> you'll likely have increased emissions that's damaging the oxygen
> sensors and catalytic converter. And if the mixture is running too
> rich, you can have a lot of carbon plugging things up too (maybe like
> EGR valve, throttle body ports, etc).
>
> So I think you should:
>
I noticed yesterday that my valve pan cover bolts were loose, would
this have anything to do with my air flow. Since the pcv valve runs
from valve cover to the intake. Every time I would blow into the port
air would just seep out of the bolt holes from where they was not
tight.
Joe
Ray O
************
I doubt it, but you probably have a pretty good oil leak going, so it is
worth tightening the bolts.
Joe
wrote:
> "Joe" <steelhors...@hotmail.com> wrote in message
Hey, its me again thought that I would write and tell you how its been
going. I was able to locate an exhaust manifold for the car that had
the 02 sensor still in it, with the original connector from the car. I
put it on and everything, and then reset the codes on my car. Before
it was showing P0125 and P0135. Now it’s showing P0135 and P0401. I
just don’t get it, when the check engine light is off the car does
fine no problems what so ever. As soon as the check engine light comes
on the car starts acting up again. When you let off the gas, the rpms
will jump down real quick below 1000, then jump back up. I figured
that if the egr system were messing up, it would possibly show the
code on the 02 sensor as well. I’m at a complete stop on here on
knowing what to do.
Thanks
Joe
Ray O
Joe
********
The engine is not acting up because the check engine light comes on; the
check engine light comes on because the engine is acting up.
P0135 is bank 1 sensor 1 (the sensor on the exhaust manifold) heater circuit
malfunction. The O2 sensor has a built-in heater to help it reach operating
temperature more quickly when the engine is warming up, and the car's
electronic control unit (ECU) has detected a problem with the heater on at
least 2 consecutive trips. While the car is out of emissions compliance,
the heater has no effect on engine drivability, particularly when the engine
is warmed up, and is unlikely to be the cause of the drivability problems.
P0401 is exhaust gas recirculation (EGR) insufficient flow detected. If the
EGR valve is open or leaking at idle, you can get poor idling or stalling,
because there is too much flow at idle when there should be none. The ECU
monitors exhaust gas flow through the EGR valve by monitoring the
temperature of the gas flowing out of the valve with an EGR gas temperature
sensor. If the sensor is bad, you could get P0401 even though the exhaust
gas is flowing properly or flowing when it should not be. I don't know the
correct voltage values from the sensor off hand, but sensor output voltage
should vary when the EGR valve is opened.
Check the operation of the EGR modulator, EGR valve (to make sure it is not
clogged or stuck in the open position), and operation of the EGR temp
sensor.
Also check the condition of the ignition system - spark plug, ignition
wires, distributor, rotor, and coil.
BTW, when I post suggestions, I try to list them in the order or likely
cause so check stuff in the order that I list them, and try not to skip any
steps. If you don't understand a step, let me know and I'll try to provide
additional detail.
Joe
wrote:
I was needing to ask you about the egr modulator. When its cold you
can plug both ends and it blows through just fine, but when its hot
and you plug both holes you can't get no air through what so ever. I
was reading a article on 02 sensors, it said something about if its
going bad then you will notice driveability problems with engine
hesitating and surging.
Joe
Ray O
Joe
********
Try this link for an explanation on how the EGR system works and how to
check the EGR vacuum modulator: .http://www.autoshop101.com/forms/h61.pdf
Not all cars have an EGR vacuum modulator. An EGR vacuum modulator looks
like a fat disc or flying saucer and has 3 ports labeled p, q, and r. If
the device you are looking at looks like a rectangular cube with 3 vacuum
ports and an electrical port, that is the vacuum switching valve (VSV) for
EGR and the check procedure is a little different.
While it is theoretically possible for a bad O2 sensor to cause a
drivability problem, in a vehicle with an OBD II system like your car has,
you would also get a trouble code relating to the O2 sensor signal being out
of range, which you do not have.
Joe
I had a question about the egr valve. When you push the diaphragm up
on the valve, will the car start to stall out. When I did mine like
that it didn't change a thing with the idling what so ever.
Joe
>
> - Show quoted text -
Is it possible for a Throttle Position Sensor to throw a egr code.
JOE
Ray O
JOE
*********
Not really. Also, a bad or mis-adjusted throttle position sensor would have
a separate code and probably cause drivability problems.
If you are still having problems, buy, rent, or borrow a vacuum gauge and
measure manifold vacuum at idle. You should have over 14 in. Hg.
Joe
If you could follow this link, and tell me if this is what you are
talking about.
Its the only vacuum gauge that any of the auto part stores around here
carry.
http://www.autozone.com/autozone/catalog/accessories/accessoriesShelf.jsp?categoryDisplayName=Tools&fromType=accessories&fromString=search&parentId=6-10&filterByKeyWord=vacuum+gauge¤tPage=1&navValue=100503&categoryNValue=100006&fromWhere=&itemId=503-10&displayName=Vacuum+Pump
JOE
Ray O
JOE
Yup, that should work. It looks like Autozone has the tool on their loaner
program, or look up "Mighty Vac" for about $40 some place like eBay.
Joe
>
> JOE
>
> Yup, that should work. It looks like Autozone has the tool on their loaner
> program, or look up "Mighty Vac" for about $40 some place like eBay.
> --
>
> Ray O
> (correct punctuation to reply)
Hey, I was going to tell you how I tested my system today. I teed a
line in between the egr valve and vacuum switching valve, with engine
at warm and just idling it was reading 3 on the needle. I then
connected E1 and TE1 on my box, and hooked Q line straight into the
tee. I held the engine at 2500 rpms and it read out about 13 on the
needle. I’m guessing this is normal, but I’m not for sure. I was
wondering if you knew how to test for an intake manifold leak, or for
a possible restricted exhaust. I also checked the vacuum lines
individually, and none of them were bad. If you could help me out I
sure would appreciate it.
Thanks
JOE
Ray O
JOE
***********
13 inches of mercury (in. Hg) is a tad low but I don't think that it is low
enough to cause problems. Ideally, you should have over 14 in Hg.
I'm not familiar with how to test for an intake manifold leak because I've
never run across one in a Toyota. Since you are getting decent vacuum, your
intake manifold is probably OK.
A restricted exhaust probably would not set a trouble code, and the vehicle
would perform poorly, like it is under-powered. If the engine runs OK, a
restricted exhaust is not very likely.
I don't remember if you have done this or not, but the next step is to
activate the EGR valve by applying vacuum directly to the modulator while
the engine is idling. The engine should start to run poorly and /or stall
when the EGR opens at idle. If you get no change in how the engine idles,
then the modulator isn't working, the EGR valve is stuck, or there is a
restriction in the tube between the EGR valve and intake manifold.
If the engine starts to idle poorly or stall when the EGR valve is open,
then check the EGR gas temperature sensor. The sensor should be right next
to the EGR valve in the tube between the EGR valve and intake. I don't know
offhand what the specified voltages for the sensor are, but they should
change when the EGR valve opens and exhaust gas flows past the sensor.
--
Ray O
(correct punctuation to reply)
The next step
Joe
I will check my egr gas temperature thing out tomorrow. Today I put
vacuum on my line that goes to the canister. It was slowly losing
vacuum, so I tried the line itself and it was good. I also held up on
my egr valve instead of putting vacuum on it. When I push up on it,
the car stalls and tries to die.
JOE
Ray O
JOE
What do you mean by "held up on my egr valve?" If opening the egr valve at
idle makes the car stall, then the egr exhaust gas temp sensor (or position
sensor if it has one instead of a gas temp sensor) is the next thing to
check.