Okay, I just did the paperclip trick, since I have been getting the SES light for a few weeks now. Time usually isn't on my side anymore to fiddle with my car, but luckily I had the day off.
Here it goes -

13 - O2 Sensor. I just replaced that last month.

31 - PRNDL Switch Circuit. What exactly does this mean? I understand what the letters stand for, but what'* wrong with it?

34 - MAF low circuit. I replaced this 3 weeks ago with a brand new one.

57 - Boost Control Problem.

58 - Pass Key. Doesn't apply since I have a remote start.


My car has been bogging down alot lately, especially under load. I'm assuming the boost problem is contributing to that.

FYI - my car was recently tuned up.

57 would be the BCS usually, a $30-ish part and super easy to replace. Does your boost gage act funny sometimes?

58 ignore like you already are

The rest... unhook the battery for 10 minutes and see if they come back.

Didn't you just do an engine swap or two recently?

The first thing that came to my mind, due to the variety of codes, is a PCM related problem. That doesn't mean you should immediately swap your PCM though...yet, lol.

First, check the PCM connectors at the PCM and at the other ends. Make sure they are tight and not corroded or damaged.

Some of the codes may be left over from the recent repairs/tune-up. First, I would clear the codes and see which ones (if any)come back. That way, you aren't chasing problems that may now be fixed. Also, I think several members have had a new MAF be bad or go bad after replacing, and maybe that has lead to some of the other codes.

I did have an engine swap done in February. I actually did replace the PCM a few weeks ago, the same day I replaced the MAF. I also have a spare SC so I just swapped the BCS and took my car for a spin. That seemed to fix the boost issue as far as the guage is concerned but it'* still bogging down in first gear. It almost redlines before shifting into second...of course that'* only when I step on it. Regular driving it shifts okay. Until going up a hill...then it boggs down again.
I did use a Bosch O2 sensor,which I'm reading are crap.
I will go clear the codes, and see what'* left.

Thanks!

Isn't that PNRD321 switch mounted at the end of the shift cable on the trans? If so, those bolts could be loose just like mine was. I dd get a CEL before my trans died, never got the code for it though.

I disconnected the battery, reset the codes, and now I have a code 56 Quad B Fault. Any ideas what this is and how to fix it?

The Code 56 (Quad B) error could be caused by the following: EGR solenoid #2 or #4, boost control solenoid, tcc solenoid orshift solenoid, or the ECM itself.
Does the SES light come on while you're coasting for roughly 5 seconds? That happened to my '92 sse */c recently, and the cause was the boost control solenoid.

FYI, I occasionally get codes 58 and the PRNDL code on my '92, but neither code appears to cause behavioral problems and I've read on this forum that code 58 was a problem with the '92 ECM.

EGR seems like it could be the likely problem because the gas mileage has dropped and when standing at the rear of the car it smells like gas. Would a faulty EGR valve cause the car to bog down? I swapped BCS for a good one on my spare SC. SES light comes on when braking underload and as well as when coasting.

I think the first symptom of a faulty EGR would most likely be a rough idle, but I've personally had different EGR problems that caused an SES light with a different code, or a lower boost reading than normal (symptom of a vacuum leak) when idling after a freeway drive.

On the topic of the fuel smell near the exhaust, I'd suspect the O2 sensor or a leaking fuel line. If you have a scan tool, it'll help diagnose if it'* an O2 sensor problem...if it'* the 02 sensor, they don't usually trigger the SES light or store an error code when they fail, you'll just get poor gas mileage. And only buy a GM O2 sensor; I can vouch for the problems others have had with Bosch O2 sensors.