My mods are as follows:
1)random technology (highflow cat that is supposedly street legal)

2) Open element K&N air filter

I warmed up my car through a 45min commute. All accessories were turned off. I'm also using 87 octane. But I still failed the hydocarbon emissions. Can any of you tell me what could possibly be wrong?

Thanks

 

did you check your egr valve? my setup is similar to yours and i had the same problem. replaced the egr and passed with room to spare.

i'd also check fuel pressure to see if it's rich, and the base timing, too. the more advance, i believe, the higher the emissions.

 

How do I check the fuel pressure? and do I get the EGR valve from the dealership? I don't think my timing is the problem, I think it's stock. Is there any use for me to put the stock air filter and catalitic converter back?

Thanks

 

I have a similar setup and also failed emissions. We wound up having to temporarily install a reducer after the cat at the flange to get enough back pressure to have the EGR function properly. I also had to swap out my Random Technologies cat due to the fact that it had become saturated with oil due to leakage past the valve seals. I have cleaned the cat in my heated ultrasonic tank but haven't tried re-installing it yet.

Lon

 

hmm....I think I know why I failed the emissions test. The inspector didn't shift to a higher gear. He only stayed on second when my car is fully capable og going to fourth gear during the emission test. You know when you try to stay in a constant speed of 25MPH the inspector left it on second gear. Well I tried it myself and realized that the shift light went on, so I assume the engine was taking in too much gas and was not burning all of it.

What do you think?

 

I thought the same thing, but it really doesn't matter much. I ran my car a couple of more times with another inspection shop before I took mine back to the "Test Only" shop I initially failed at. That guy told me the test operator can shift the car or not. It is up to him. Not dictated in the emissions certification standard. If your car is puffing blue smoke at start-up you may have coated the cat. Bad news considering how expensive they are. I still haven't rebuilt my engine so I'm keeping the RT cat off until then. I borrowed a good 4th Gen cat that we modified to work. Check that your EGR is working right. If you take it off and find it badly covered with carbon you should clean it. You may want to try the back pressure trick. I had the EGR replaced the prior emissions test. It is a GM unit. I was told that some aftermarket EGR's have different diameter orifices that you can swap out to make the EGR work with the low restriction cat-back exhaust.

Good luck, Lon

 

As far as I know my car isn't puffing out blue smoke. So I'm guessing it's the EGR.

edit: I just called a guy a parts store and I told him about my situation. He said to put one bottle of rubbing alcohol in the gas tank. Has anyone ever tried this to pass emissions?

Thanks

 

what shape are your plugs in? also, do an oil change.

from what i've read, sunoco gas is very low in sulfur content and other things that cause emissions to rise (i won't get into the chemistry or anything...).

 

they should be in pretty good condition. I just changed it about 9000 miles ago. I also just did an oil change yesterday.

 

might also want to try the O2 sensor and PCV before the EGR. O2 sensors cause the most emissions problems of any engine part... and less than half the cost of an EGR too.

 

just changed those (O2 sensor and PCV valve) too...so it might actually be the EGR

 

well, i think i inadvertently bought an EGR for a TBI from pep boys (well, i requested one for TPI and it was wrong when i got home), and it was about $55. i don't think they're all that hard on a TBI either, at least not as much work as on TPI...

 

Is there anyway for me to check if the EGR is bad? How do I know/tell?

Thanks

 

Failing HC is a result of an incomplete burn in the combustion chamber. Most TBI camaros run leaner after switching to an open element. I had the same problem but, after increasing the fuel pressure to 14psi from 12psi The HC readings passed with no problems.

The EGR valve affects the NOX levels. if you passed the NOX part of the test, the EGR valve should be working fine.

 

How about I just put the stock air filter back? Will that help fix my problems?

 

Yes, that should help even out the air fuel ratio enough to bring the HC level down.

 

i had the same mods as you and failed by like.8 in the same things and i got a new egr valve crap the thing that looks like a gold yo-yo replaced that and then put back the stock air cleaner assembly and put in 92 octane and then put 2 bottle's of that stuff with the horse on the bottle and passed by .2 .