Well just last september I did an entire upgrade of my exhaust system (85 tpi) with the following emissions legal parts, hooker headers /w air, new random tech cat /w air, k&n cold air kit and hooker catback, so I should be legal right.... wrong these are my results
LIMIT READING
HC(ppm) 108 118
CO% 0.60 0.08
NO(ppm) 1161 1862


I don't know what I can do to make it legal, its not too far off (I think), any suggestions? Could it be running lean/rich? Do you need to make sure the cat is warmed up? Anyways I was looking at my 91 4 banger Tercel and its limits were HC=111, CO=0.62 and NO=1307, could anyone tell me why a car with 4 less cylinders, 3.5 litres smaller and 6 years newer be allowed to have more pollution? just wondering hehe


thx

 

A cat will not work well unless its fired up. ie really really hot. Another issue is your car has to be at operating emissions temp. From what I recall, really hot, like 225 region for temps to help with combustion. I can get mine to pass with no prob, but mine's an 88 TBI so not sure how much different the standard is. Here's what can help, a tune up and an oil change. Need the ignition system to be running at peak efficiency to ensure good combustion. The air system is suppose to be a fall back contingency type deal for when O2 prior to the engine is harder to come by. Since you are running cold air to the system should be alright, just try the tune up first.

 

Change the oil and fill up with Sunoco Ultra 94.
Verify stock base ignition timing.
Verify EGR valve function.
Be sure the motor and cat is hot
when tested. An infra red gun can be used to check
converter temp. Your oil gets fuel soaked fron city driving. The Sunoco gas burns cleaner
(10% Ethanol) and lowers emmisions. Go to a different test station.
Still $15 to retest.
Disconnect ( disable) the electric plug on one fuel injector. This cylinder will pump only air and dilute the emmisions to passing spec. with pure air.
Go to the driveclean internet site and download the driveclean testers guide and check your car/motor in the charts to ensure the
online computer tested you against the proper standard.
test weight/ liter.

 

Check your PCV valve?

 

I just found out that cars that have more weight must produce better results and they have my camaro as 1814 kg, so basically 4000lbs !!!!
what have they put for your camaros/firebirds?

 

Mine was tested @ 1814KG too.
A result with a high HC and NOX reading
could be caused by a slightly too lean air/fuel ratio
(o2 sensor, vaccuum leak,dirty injector.)
and a malfuntioning EGR valve. or over advanced timing.
An over rich mixture usually results in a high HC
and low NOX reading.

 

I did the mistake of testing with a faulty EGR.... nox shoots up 4 times what the limit is. So don't worry too much about the EGR unless you get a code 32 or have insanely high nox levels. As far as HC and CO, CO is the result of incomplete combustion (back from my old chem eng days) and HC is basically unburnt fuel or partially broken down fuel. An octane can break down into septane, hexane, pentane, butane, propanes and methanes if only partially combusted. A tune up and oil change will give you your peak efficiency for combustion, after which then you can start to determine which other parts are broken. An ECM getting the right readings from all its sensors will make a very good reading and the cat with AIR system will cut it down further. I managed to get all my readings down to less than 1/2 the requirements. As for gas I only use sunoco gas, I think was reated cleanest fuel mixture for all of Canada with Esso being the worst with the highest sulfer count. Another way to ensure a passing reading is proper engine temperature. GM sbc's are notorious for being engines that have to run HOT to pass emissions. Odds are we all make our engine's colder lol.

 

well, thanks for all your help. I've gotten an oil change, was using 87 gas from who knows where, will put in 94 sunoco for the next test. Still have to check the EGR, but I have put a new O2 sensor and thermostat in september as well. We'll see what happens. I think it could also be running lean because of the exhaust/intake mods. Thank *** this will be the second last emissions test ever for this car hehe.

 

Thats funny that they bleep out *** (gawd).... retarded... I can probably say Satan without it getting bleeped, but *** (gawd) is a no no... sorry, just venting

 

when i bogut my car from a gm dealer it woudlmnt pass emissions cuzz it didnt have a cat on it....so they threw one on her and she still didnt pass.....it was runnin to rich theys aid.......so gm didnt do it they took it to a performance shop and got it done there.....they tuned it down so it wasnt runnin so rich then passed itt hen hopped it back up.....maybe try that

 

I passed a couple of months ago without an EGR with flyin colours. What u should do is retard the timing and use Sunoco 94. Also take your car for a blast for about a half hour before.