How do I decipher these codes?

[jtltoy]

Hi,
I recently changed both o2 sensors on my 1993 SHO (3.2L). I disconnected the battery to allow the computer to reset itself. Then I brought it done to Advanced Auto and had them do a test on it. It came up with these codes, but I haven't been able to figure them out. Can someone tell which parts need replacing?

 

[LOUDSHO92]

You need to replace your O2 sensors and clean the paths to the EGR.

 

[Ultymte]

...and in case you don't have it, here is a list of codes for future reference. This has helped me become even more confused in the last few days

 

[jtltoy]

I just changed the o2's and it runs alot better. It still has a hesitation when I give it gas when it is cold.

 

[SASHO91]

actually if they are new, and the EEC has been cleared... i would say you have a leak somewhere on the intake, letting un-metered air in, resulting in a lean condition....

and as Matt stated, cleaning the EGR lines/nostrils(in the intake) would be the way to proceed with those EGR related codes.

 

[jtltoy]

What does EEC stand for? I took off the throttle body and looked around. I'm not sure what I'm looking for.

 

[SASHO91]

EEC= the sho's computer....

you really cant see the leak....
what you can do, is get some carb cleaner(i think) and spray the intake. Spray around the cupplers, mating surfaces.... etc... do this when the car is on... if at anytime, you hear the idle raise up from you spraying the carb cleaner, thats were your intake leak is...

 

[jtltoy]

Thanks for the tips, I'll try that. One other question. Has anyone ever used one of those retrofit A/C systems. They claim you don't have to change anything but the fittings. It seems to good to be true.

 

[projectSHO89]

Thanks for the tips, I'll try that. One other question. Has anyone ever used one of those retrofit A/C systems. They claim you don't have to change anything but the fittings. It seems to good to be true.

.

It is. They're called "death kits" for a reason.

You don't have an intake leak. You do have an A/F issue though, but the opposite of the usual ones. 172/176 combo means that it's running too rich even after the computer has gone max lean.

 

[projectSHO89]

Thanks for the tips, I'll try that. One other question. Has anyone ever used one of those retrofit A/C systems. They claim you don't have to change anything but the fittings. It seems to good to be true.

.

It is. They're called "death kits" for a reason.

You don't have an intake leak. You do have an A/F issue though, but the opposite of the usual ones. 172/176 combo means that it's running too rich even after the computer has gone max lean.

You also likely have a faulty DPFE sensor. I'd also bet you hace clogged EGR ports.

Have to look up the 18X codes tomorrow, don't recall having seen them before.

See my signature?

Steve

 

[jtltoy]

So what controls the A/F mixure?

 

[projectSHO89]

The EEC (PCM) does based on its inputs and its programming.

You will reallly need to learn how to run the KOEO, KOER, and Cylinder Balance (CBT) tests to diagnost his set of faults.

My response from memory last night was not accurate regarding the A/F mixture and the 17X codes.

172/176 means that both O2 sensors are reading lean.

The 181/189 codes indicate that the PCM has maxed out the fuel trim.

See the conflict?

You'll need to reset the PCM and rerun the KOER PCM Quick Test instead of driving it anywhere. This will focus troubleshooting into exact duplicatable conditions.

Go practice pulling codes.

BTW what brand and part number of O2 sensor did you use?

Steve

 

[jtltoy]

They were Bosche sensors, part #15716. They did look a little different from the ones I pulled out, but that happens alot.