I have a 96 Chevy Blazer with 4.3L engine. It is a 4 X 4 but the question is this, the check engine light just started coming on. At first it didn't seem to be anything at all. Now, when I first start up the car it hesitates upon acceleration. In my old blazer, I just needed a paperclip to read the codes, anyone have any ideas and do I have to take it somewhere to have the codes read?

 

Autozone or Advanced Auto will read the codes for free and should be able to give you a print out listing the codes.

Once you get them read, report back here and we'll try to diagnose the problems. Just because you have a code for, say, an O2 sensor, doesn't exactly mean that the O2 sensor is bad, it could mean that you have a vacuum leak or a host of other problems.

 

Thanks Kyle,

Autozone read the code. There was one and it was P0101. They said it was a map sensor or air flow sensor??? They erased the code and the car seems to run fine. Before, it hesitated upon acceleration. Any Idea's?

thanks,

Dennis

 

P0101 - Mass Air Flow System Performance

Do you have or have you ever had an aftermarket, reusable, oiled air filter on your truck (aka K&N)? If you have, it is VERY likely that the oil has coated the MAF, causing it to read incorrectly. To clean the MAF, remove it from the intake tube (noting its orientation), disassemble it (remove the 4 screws around the outside) and thoroughly cleaning the screen and the sensing elements with electrical contact cleaner. If the MAF is really dirty or hasn't been cleaned in quite awhile, you may have to spray some cleaner into the cap from the can and use a q-tip on the elements. BE VERY CAREFUL when attempting to clean the elements. They are soldered on and have VERY fine wires. The MAF is not cheap so DON'T break the wires!

I clean my MAF and EGR valve at every oil change.

The oil on a K&N filter will coat the sensor elements. When this happens, they are much more prone to having the fine dirt, that makes it through any filter, coat the sensor and cause incorrect readings. GM has a technical service bulletin (TSB) on this. A dirty MAF can cause a whole host of problems that aren't limited to the engine (tranny can be affected as well).

Give that a try. Again, I'll say take your time and BE CAREFUL!

Good luck

 

I had the same problem and it was the egr. Funny thing is it only did it when it got warm.