cold start valve as proxy for frequency valve?

[Andrew Seidel]

All,

Good to see more activity on the group recently!  My 500SEC euro was gray-market imported with pre-cats and o2 sensor in lieu of the full system that came in the next year's US version.  My pre-cats are wearing out, but also my local emissions test inspector has been pushing me to put in a complete system with mixture controller and frequency valve (for some reason, he agrees the smog pump was never part of the requirements of that time) .    

As you may know, the fuel plumbing of the FD is quite different between the euro 500 and e.g. my US 560, so adding the frequency valve would be a tricky hybrid system to create.  My question:  do you think I could splice in to the existing cold-start valve for enriching the mixture (I guess you would lean-out the normal running mixture so you could swing both ways about nominal)?  Including, would there be any long-term issues?

Also, has anyone else installed the Magnaflow pre-cats on a euro and were you happy with the results?  My pre-cats actually came out of a W201 and are a little narrow and causing a buzzing at the headers.

Thanks!  

Andrew Seidel

85 500SEC

86 560SEC