phantom check engine light

[Invictus]

i have a 97 blazer 4wd and about 2 weeks ago the service engine soon light started comming on randomly and going back off..so i took it to midas and had them run a diognostic but they said since the light wasnt on at that moment they couldent tell me what was wrong...its not the plugs or the air filter its not any of the hoses...im dumbfounded if anyone has any idead please let me know

[rlith]

Ok, they're idiots.... Take it to autozone, if the SES light came on and went off, it still stored a code... Autozone will read it for free...

[G8TOR]

I had the same problem we were told to switch the kind of gas we were using. I always used a higher octane fuel, but once I switched over to regular after a couple tanks of gas the light has never come back on.

Hope this helpsn never hurts to try

[rlith]

Still, the code should be pulled... It could be something else besides bad gas causing the egr to act up..

[madmonk210]

My 93 blazer does the exact same thing. The light comes on anytime it wants then I get a loss of power. my truck gives me code 43, when I check it.

[rlith]

Originally Posted by madmonk210

My 93 blazer does the exact same thing. The light comes on anytime it wants then I get a loss of power. my truck gives me code 43, when I check it.

One of your knock sensors are bad...You have 2... 1 directly below and between cylinders 3 and 5 on the driver's side of the block, and one behind your passenger side head between the firewall and the head.... This should be addressed immediately as it controls your timing and can lead to other severe issues...

[GMMerlin]

Originally Posted by Invictus

i have a 97 blazer 4wd and about 2 weeks ago the service engine soon light started comming on randomly and going back off..so i took it to midas and had them run a diognostic but they said since the light wasnt on at that moment they couldent tell me what was wrong...its not the plugs or the air filter its not any of the hoses...im dumbfounded if anyone has any idead please let me know

If the SES light comes on, a code is stored in the PCM.
It can be read with a code reader or bi-directional scan tool. The code will be the key to what is wrong with your vehicle.
Question...why would anyone take a driveability concern to a muffler shop...its like having the electrician look at your plumbing problem

[Invictus]

they were the only place that could run a diognostic and i wouldent have to wait 2 hours...the light hasent come back on since the day i took it but im still having my transmission problem..i posted awhile back about it and got no reply ...the thing is it hits second gear real hard hard enough to bark the tires under half throttle it kinda clunks hen it goes to third and 4th is a seamless shift ...the fluid is clean the filer is relatively new and the tranny was rebuilt 20,00 miles ago so im completely lost on what the problem would be

[rlith]

If it was built only 20k ago, then it should be under warranty... Like I said, go to autozone, the code most likely is still stored in the ECM

[GMMerlin]

Originally Posted by Invictus

they were the only place that could run a diognostic and i wouldent have to wait 2 hours...the light hasent come back on since the day i took it but im still having my transmission problem..i posted awhile back about it and got no reply ...the thing is it hits second gear real hard hard enough to bark the tires under half throttle it kinda clunks hen it goes to third and 4th is a seamless shift ...the fluid is clean the filer is relatively new and the tranny was rebuilt 20,00 miles ago so im completely lost on what the problem would be

First have the code pulled..Autozone will do it for free.
The transmission shifting concern could be a result of another failure causing the SES light to come on or an internal trans problem..the code will be the clue.

[30 pak]

Hey,mine was dooing the same thing shifting reel hard from 1st to2nd only when the light was on when the light went out it ran like new. My light hasnt come on for over 2 months so I havnt had to jack with fixing it but the same thing hapened to Super Dawg and he said it was the throttle position sensor But like merlin said Go run codes from somone who specializes in something other then trannys just to be sure.

[30 pak]

yesterday mine started doing the same thing for the 5th time. SES on, barking tires from 1st to 2nd, runnin like shit. Ran my codes Turned out to be the same thing as Superdawg Bad Throttle Position Sensor. Replaced it,no SES light runs like new.

[Invictus]

just got 3 questions...how much does it cost ...where can i get it from...and how do i replace it

[30 pak]

Any major parts store will have a TPS Ipaid 27$ at auto zone took 15 minutes 1st pull your bowl cover off your carburator or throttle body. On the drivers side of your carb or throttle body at the base you will see 2 sensors the one closest to the front of the car is the Throttle Position Sensor to make sure you have the right one when you unplug it it will have 3 wires 1black 1blue 1gray 2bolts pop the old one out pop new one in+put back together. After replacing TPS SES light might still come on To clear the old code unhook the negative battery cable for afew minutes+ hook back up should be good to go. oya the 2 bolts are torx bolts you will need atorx bit.

[Invictus]

i replaced the throttle posistion sensor and the problem dident fix . the check engine light doesnt come on anymore but it still shifts into second much harder then it should .when the codes were ran nothing was wrong with it .so if anyone has any ideas