It's a 94 formula with kooks longtubes, 3" Kooks Y-pipe, Magnaflow hi-flow 3" cat, and 3" TSP Rumbler exhaust. This car passed emissions with the same exact setup 2 years ago. I took it to a dealership, and they found 3 possibilities.

1) O2 sensors are not plugged in. However, they were unplugged 2 years ago when I passed emissions.

2) EGR Solenoid is bad. I'm having this fixed, but I'm curious how it might effect emissions. Anyone care to explain what possibilities a bad EGR solenoid might produce?

3) I have an aftermarket cat. The tech said that it's likely since it's hi-flow and aftermarket, it wears down over time and doesn't produce emissions results the same as when it was brand new.


The emissions results - I don't have them in front of me, however they tested for 3 things

1) I forget - 1.00 grams per mile allowed...My car was 1.90g
2) Hydrocarbons - 12.00 grams per mile allowed....My car was 27.xxg More than double allowed.
3) I forget - 2.00 grams per mile allowed...My car was 2.80g.

Almost everything was doubled. HOWEVER, Another twist to the problem. AFTER I got it emission tested 2 years ago, I took the cat out and ran a cutout for about 1 year up until a week before the emission test. SO, is it possible the converter was put on backwards? I am wondering if that is a possibility also. This is the exact converter I have. http://www.jegs.com/i/Magnaflow/642/94319/10002/-1

Sorry for the long *** post, but I'm trying to get an idea of all the options and possibilities. Oh yea, and they also said the car was running lean and it was pulling fuel. Can that be cause by any of the above?

I really appreciate any help.

 

As long as the AIR tube on the car is point toward the front of the car, its on correctly.

And the EGR issue, was it throwing a code? EGR will produce high NOx readings if its not functioning correctly. Im actually trying to pass right now too. lol

Could try seafoaming it? Idk just throwing out suggestions.

-mark

 

You could try looking the car over for any vacuum/exhaust leaks. If you have unmetered air getting past the MAF sensor, you can create a false lean condition which would cause excess fuel to be used. Is there a reason why the 02 sensors are unplugged? Without the sensors being plugged in, you are going to stay in open loop which will also use more fuel then necessary. If your emissions regulations requires you to pass with a certain level of Nox, then yes, a faulty EGR valve can cause you not to pass. As for the aftermarket cat being faulty, it is hard to say for sure. I would eliminate the other issues first and then see where you stand. I don't know if a high flow cat will wear out faster, but they may not "scrub" the exhaust gas as well either versus a factory cat.