Hey everyone im pulling my hair out and tired of throwing money at the problem. My 1997 blazer with a 4.3l vortec is running a little rough at idle and sometimes stumbles when you take off but it never dies I have replaced plugs wires dist. rotor air filter and ran seafoam for a couple of tanks one place says injectors which im not leaning towards and another says MAF I have cleaned the mass air flow and it changed nothing .... I can unplug the sensors and it runs the same with or without it plugged in could this be the problem????? im also thinkn the cat may be plugged any help would be greatly appreciated

 

I have a 97 four door that was running rough when i got it a year ago. Changed the injectors, still ran rough/rich. Took the cat off and with a crow bar and hammer completely hollowed it out. Ran way better after this but still idled rough. Replaced all o2 sensors. Bam. Runs like a beast now. Hope this helps!

 

Guessing your problem is how you end up throwing money at it. You just have to do the right tests and diagnose the problem and replace what has failed.

First of all, is the check engine light on?

Do you have a fuel pressure tester? If not borrow one or buy one at like harbor freight for 30$. Test the fuel pressure, Just search it in the forums there are a million write ups on how to do this.

 

have you tried cleaning your EGR Valve? it solved my rough idles

 

can you test the EGR valve?

 

Yes the engine light is on and i have had oreilys pull the codes and i have taken it to a couple of shops and everyone seems to say its something different than the other person i have heard injectors, MAF, EGR, Cat, O2 sensor, plugs and dist i have cleaned the MAF which made no difference which is weird i can unplug it and it runs just the same

 

Do you have the codes themselves? I know at autozone they will pull the codes for you and print you out a little receipt type thing that has the codes on it.

 

yes one was for a cyclinder 6 misfire which is why i changed the plugs wires rotor and cap the other was for a heat sensor

 

https://blazerforum.com/forum/articl...leaning-40424/

check out that article, its fairly simple and my rough idle especially at startup and at lights went away completely

 

ok cleaned out the EGR it was dirty runs a little better but still idles rough but that got rid of all the codes but the cylinder 6 misfire code came back after about an hr im down to cutting off the cat or changing the maf sensor both are kinda expensive