Will this get me to pass smog?

[Brandontw]

551-Iac circuit fault

136-O2 sensor, bank 2?

332-EGR valve not opening

Also two more that I didn’t get form him. He said one referred to the MAF so we cleaned it off. And I am not sure what the other one was; it didn’t come back the second time I guess.

I don’t notice any significant driving problems, but I also haven’t driven any other SHO. The smog guy said he thinks it’s running rich, so I am not sure what to do. Check engine light seams to come on when I am going fast but then seams random at other times.

Car is 92 MTX with custom exhaust.
I just got a sensor (only 1 for now) and installed it in the front exhaust manifold, car runs a bit different now, but only a bit, if any. The code was for bank 2 and the guy told me to switch the sensor in front so that’s what i did. I got it from kragen, 42.99, its a Borg Warner. i also cleaned the MAF sensor as i may have already said. Do you guys think that this will be enough to pass my smog? And if you think the EGR valve problem is the main thing please leave feedback on how to clean the nostrils and how hard this project is, I am only a novice mechanic, but I get a clue quick. I work on a lot of other stuff that is not cars.

 

[projectSHO89]

It helps if you post the failing numbers, whether it be NOx, HC, or CO.

Each has its usual set of causes.

Is your car a California car? If not, it shouldn't have EGR.

Steve

 

[Brandontw]

well im in nevada but it may have come from california, but i have my report from my failed smog i passed the high rpm but failed the idle HC 344/220 and my high rpm co% was 1.47/1.20 and low rpmCO% 1.42/1.20

 

[projectSHO89]

Here is the checklist from Missouri's emissions test program about failure causes:

Here are some common causes for the production of these three pollutants.

CO Failures (carbureted vehicles)

Engine not at operating temperature. Example, engine/cat cooled off while waiting in test line or has a stuck open or missing thermostat.
Bad or misadjusted float level.
Plugged air bleed passages or misadjusted main metering system, leaking fuel passages or gaskets.
Maladjusted idle air/fuel mixture screws.
Ruptured or sticking canister purge valve.
PCV plugged or drawing in fuel contaminated oil vapors.
Malfunctioning mixture control device.
Malfunctioning computer inputs. Example: Defective O2 sensor, reading lean all the time. Clogged or broken MAP sensor vacuum hose (reading a heavy load all the time). Coolant temperature sensor having high resistance or open circuit (reading "cold engine" all the time). Throttle position sensor stuck or open ground, (reading wide open throttle).
Contaminated, restricted or bad catalytic converter.

CO Failures (fuel injected vehicles)

Any of the computer components listed above.
Leaking or bad injectors.
Mass Air Flow sensors (voltage or frequency being too high).
Fuel pressure too high (restricted fuel return line or stuck fuel regulator)
Ruptured fuel regulator (fuel leaking directly into intake)

HC Failures (all vehicles)

Engine was not at normal operating temperature.
Ignition system malfunction. Spark failing to occur for any reason will send unburned hydrocarbons (HC) down the exhaust pipe. Example: bad plugs, plug wires, distributor cap, rotor, coil wire, coils, etc.
An extremely lean fuel mixture that causes misfiring. Examples include disconnected, leaking or misrouted vacuum hoses, intake gasket leaks, EGR stuck open, low fuel pressure.
Over advanced timing. Insufficient spark duration.
Low compression or mechanical problems. Worn rings, burned valves, bad or misaligned timing gears.
Over rich fuel condition causing both HC and CO failures.
Contaminated, bad or restricted catalytic converter.

NOx failures (all vehicles)

Improper operation of the EGR valve. Stuck open, obstructed, leaking, or misrouted EGR vacuum lines.
Plugged EGR passages. Carbon build up in passages.
Over advanced timing.
Too lean of fuel mixture.
Engine's cooling system in poor condition, causing excessive temperature.
Malfunction of the electronic spark control (ESC), and knock sensor. Computer fails to retard timing.
Contaminated or bad catalytic converter.

***End Quote***

It is suggested that O2 sensors be replaced in pairs. If one is bad, the other probably isn't far behind.

"Custom exhaust" - Does it still have cats installed? Maybe they're dead or gutted....

Your EGR system is non-functional. If they test for NOx, you would fail that portion also.

There are many threads about troubleshooting and correcting the 332 code and a few for the 551 code.

I am not optimistic that you will pass now with the limited actions you have taken. However, only the actual test will tell for certain.

Steve

 

[Brandontw]

Hey guys, well i passed my smog fine today, so it must have been the o2 sensor. but i had to slip the guy a little money to overlook the fact that my car doesnt have cats. cause theyre required by law here.