No Check Engine Light, multiple engine codes
 

Hi, I've been having some driveability issues lately, particularly noticeable in hot weather. This is St. Louis and we've been running 90s and some 100s. I've noticed for a while that the car was running a little rough, but as the outdoor temps got high, the rough running got to the point I wasn't sure I would make it home. I haven't gotten a CE light yet, but I pulled the codes and found 32,37, 56, and 22. So oxygen sensor 1 and 2, knock sensor and EGR system. EGR valve was changed at 100K, car is at 150K now. It's a 94 LSI, if it matters. Can anybody suggest a plan of attack outside of just replacing the sensors? Thanks in advance for any help. Also, if anybody knows anyone in the St. Louis area who really knows how to repair SVXs, I'd appreciate hearing about it. Thanks.

Re: No Check Engine Light, multiple engine codes
 

It would appear that you have detected stored codes indicating intermittent problems, possibly all caused by a single common fault.

Refer to the how too section and clear the codes and then check again after further running. Whatever then registers can then be taken as indicating current faults.

Also check that the CE light illuminates with others when the ignition is turned on, this being the worthwhile built in check for faulty bulbs.

Re: No Check Engine Light, multiple engine codes
 

Hi, I reset the codes, drove for about 5 days, and see the following codes, 56, 22, 32, so oxygen sensor, knock sensor and EGR system. Any conditions common this group of codes? Thanks for any assistance.