SES woes...WTF?

[speedracer95v6]

OK, I've always had my SES come on after I go to over 55mph and then slow down. I thought i would fix this maybe by cleaning my o2 sensors (never replaced at 145k miles).

So i clean them with b12 chemtool. Same problem. Then it gets worse and comes on while just sitting and stuff. My gas mileage (peak highway) is like 17mpg.

So today I just went out and bought new o2 sensors. The car seems to run a little better and the SES doesnt come on under 55mph...I can sit all day and it stays off. Hopefully my gas mileage will improve also.

The crap part is, I took it up to about 80mph then brought it back down...once i slowed below 55mph..the damn SES came back on. WTF? I'm pretty sure I have eliminated the o2 sensors since they are now brand new bosch sensors...but I can't figure out what the problem is.

The gas cap is on good too. It seals tight and hisses when I take it off.

Any ideas on what the problem could be anyone?

[98Camaro3.8]

Get it scanned. Don't waste money guessing what the problem might be. Let the car tell you.

[Turbo V6 Camaro]

well your O2 needs rep[lace any way but it could be you TPS

[pontiac nino]

disconnect you're battery for a lil' bit, sometimes obd1 o2's act up, they suck. egr kinda sucks too

[HBHRacing]

I'll just point out that you can not clean 02 sensors.


get it scanned to see what you have for codes. but I am banking on an EGR fault.

[speedracer95v6]

Getting it scanned means i have to take it to the dealership (obdI computer, obdII connecto = no autozone/oreilly's scanner will work).

I hope the dealer doesn't charge too much.

On the o2 sensors, I didnt think cleaning would help, but i figured why not? I did end up getting the darn $21 bosch ones though...much cheaper than i dreamed they were.

[HBHRacing]

check some other shops.. they can be cheeper.. but if you don't spend the money for a scan then you will just spend more throwing parts at it.

[Die Ford V8]

go to shucks or autozone and borrow their scanner and use it in the parking lot. you just give them your drivers license and they will give you the right scanner and all to use real quick. then give it back and they will plug it into their computer which will print out the codes and it explains stuff about the sensors or what might be wrong.
you scan it there and look in your manual you will have just as good or better a chance at figuring it out than a shop. a dealer may know more, but sometimes they are rookies and dont know much about it which ends up costing more $$$

good luck. BTW dont be suprised to find a bunch of other stuff wrong too. like speed sensors or whatever. most likely linked to the egr or Map sensor though

[Turbo V6 Camaro]

Originally posted by Die Ford V8:
go to shucks or autozone and borrow their scanner and use it in the parking lot. you just give them your drivers license and they will give you the right scanner and all to use real quick. then give it back and they will plug it into their computer which will print out the codes and it explains stuff about the sensors or what might be wrong.
you scan it there and look in your manual you will have just as good or better a chance at figuring it out than a shop. a dealer may know more, but sometimes they are rookies and dont know much about it which ends up costing more $$$

good luck. BTW dont be suprised to find a bunch of other stuff wrong too. like speed sensors or whatever. most likely linked to the egr or Map sensor though

he has a 3.4

[HBHRacing]

I think he means actualy "renting" there OBDI scanner that they sell... which will not work on a 95 anyway..

[Die Ford V8]

dont know what you guys are talking about, but i scanned my friends 94 firebird with a schucks scanner and it worked just fine.
JUST SPECIFY WHAT CAR YOU HAVE!!!!!!!then they will give you the correct scanner!!!


i have scanned both my camaro(96 3.8) and my friends firebird(94 3.4)

[Die Ford V8]

there isnt a difference between a 94 and a 95 computer is there?

[speedracer95v6]

95 is the freak. It is OBDI but has an OBDII scanner port. The regular OBDI scanner won't connect, and the OBDII scanner will connect but will not work as I have an OBDI car...lol..it's ridiculous.

Autozone here doesnt have one. O'reillys doesnt have one. They both say to go to the chevrolet dealership, which unfortunately I think I will be forced to do.

[tWiStEdBird]

My 3.4 did that. The problem was the EGR. Dont ask me why it only did it at certain speeds, but it sure as hell did.

[speedracer95v6]

Now how do I fix the EGR? I thought that it was just about retarded that it did that only after going certain speeds...glad I'm not just seeing things.