Emission Problems
#1
Emission Problems
Today was my third try at passing emissions and I failed once again. My test results were HC 618 with 53 allowed and CO 0.98 with 0.28 allowed. So far I have replaced the cat converter, plugs and wires, O2 sensors, coil and control module, header gaskets, opti spark, ecm. I'm running out of options real quick because my registration expires in 4 days and won't be renewed until I pass. My car is a 94 Z28 with 79000 miles and I thought in great shape. Any and all ideas will be greatly appreciated. Thanks
#2
Re: Emission Problems
Have you checked the fuel system, ie fuel pressure, injectors, fuel filter?
618 HC it's running way too rich.
Was the cat just replaced or awhile ago? You may want to recheck it.
618 HC it's running way too rich.
Was the cat just replaced or awhile ago? You may want to recheck it.
Last edited by EDS Z28; 07-01-2006 at 03:19 PM.
#3
Re: Emission Problems
Thanks for the reply. I yesterday replaced the cat again w/ a known working unit, and checked fuel pressure..42 lbs. Retested and got even worse results...HC 913, CO 184. I ordered another set of o2 sensors because I always get the 4 wire setup, which I'm confident that I wired correctly. Hopefully I'll get a 2 wire setup this time. Again guys I'm desperate I have to pass to get my reg renewed. Please help
#5
Re: Emission Problems
Once again thanks for the reply 180 thermostat, started at 160 Hypertech... PCM tuned to my cam and start fans at 180. I going to have to sell my car if I can't figure this out.
#6
Re: Emission Problems
I had troulbe passing when my fans were set at 200. The hotter setting would help heating up the cats. setting to fans back to stock would help, but i bet the tune you have is running a little fat..
#9
Re: Emission Problems
Originally Posted by BIGMAC
....I ordered another set of o2 sensors because I always get the 4 wire setup, which I'm confident that I wired correctly. Hopefully I'll get a 2 wire setup this time. ...
What are all the mods to the engine? You mention headers..... what else?
#10
Re: Emission Problems
I have no idea how emission testing is done since I live in MI, otherwise i might be able to help you.
Have you ever passed with this cam? and has it ben tuned?
Have you ever passed with this cam? and has it ben tuned?
Last edited by "White Knight"; 07-06-2006 at 12:21 PM.
#11
Re: Emission Problems
Once again thanks for the advise and sorry for the late reply. Well after getting my car scanned the garage concluded that the optispark (new) and the cat was bad. So once again I replaced the optispark and cat with BRAND NEW parts. Guess what? I failed again but got closer, HC 490 and CO 1.97. Today I got the car rescanned and everything looks 100% yet I still failed.
As for the 02 sensors my car originally had only 2 wires running to the sensors for the unheated version of 02's. My car has the same mods it had before when it always passed no problem..biggest mod would be the hot cam..everything else just basic bolt ons.
Thanks
As for the 02 sensors my car originally had only 2 wires running to the sensors for the unheated version of 02's. My car has the same mods it had before when it always passed no problem..biggest mod would be the hot cam..everything else just basic bolt ons.
Thanks
Thread
Thread Starter
Forum
Replies
Last Post