Another SES question....

[TopHatJimmy]

I have a 1995 3.4L auto, and for awile now, I have this problem with my SES light coming on.
If I'm on the freeway doing like 70 and I have to slow down for traffic or to get off the freeway, as soon as I hit about 62mph, the SES light comes on. It also does it if I'm cruising around town at say 35 to 45mph and I want slow down a little by shifting into 2nd and leave it there for more that 5 or 10 seconds.
I can't scan the car, I had Autozone try, but he said I have an OBDI computer and an OBDII diagnostic plug, so the OBDI scanner won't plug in and the OBDII scanner doesn't recognize the computer.
I have a feeling it has something to do with my EGR, but don't know what. Hate to toss away $300 + for a new one if mine just needs to be cleaned out....

[Renzo]

I have the same problem...... with my 95 3.4 Firebird

[CARdiac]

Ok, let me try to explain.....IT IS THE POS EGR!!!! I have a scanner and it get solenoid 2 and 3 errors.....I still get the codes even after i put in a new egr and piping....seem like a problem w/3.4s...

BUT

have your codes read just in case, I bought a scanner from This Guy and I have been very happy...look for a remanufactured one..it will read the codes but not clear them.

[redline360]

I have the same problem 3.4 auto 94. When i get abouve 60 or so and slow down the SES light comes on or whenever i cruise at a certain speed for a period of time it comes on. Really dont understand it cause when i beat the hell outa my car it never comes on just when i cruise for a bit

Its deff the EGR. Try cleaning it first im just to cheap to get a new one

[HBHRacing]

if you get a lot of EGR faults even after you change the EGR you could also have a bad map sensor. however.

9 out of 10 times it's blocked EGR passages in the intake. I see it time and time and time again. Only about 10% of EGR codes are a true pintal fault. Most times it's due to the passageway being blovked with carbon.

[vallentinerocks]

Re: Another SES question....

been dealing with exact same problem for months. now i have to get smogged. hooked up my scan tool, seems to throw code 43. but then it also indicated 73 or 75, but it was EGR solenoid 1 problem. I changed out the ignition module yesterday as suggested by one of my automotive instructors, but than did not cure problem. on my way now to swap back old ignition module and then change MAP. if that doesnt fix it, then im cleaning the EGR before i try to replace it.

[95redslp]

Re: Another SES question....

Ok, let me try to explain.....IT IS THE POS EGR!!!! I have a scanner and it get solenoid 2 and 3 errors.....I still get the codes even after i put in a new egr and piping....seem like a problem w/3.4s...

BUT

have your codes read just in case, I bought a scanner from This Guy and I have been very happy...look for a remanufactured one..it will read the codes but not clear them.

you need a scanner that will reset them...

[95redslp]

Re: Another SES question....

been dealing with exact same problem for months. now i have to get smogged. hooked up my scan tool, seems to throw code 43. but then it also indicated 73 or 75, but it was EGR solenoid 1 problem. I changed out the ignition module yesterday as suggested by one of my automotive instructors, but than did not cure problem. on my way now to swap back old ignition module and then change MAP. if that doesnt fix it, then im cleaning the EGR before i try to replace it.

did not realize how much of an old topic you bumped.... anyway... ebay has these egr's new for MUCH cheaper than dealer or parts store

[vallentinerocks]

Re: Another SES question....

new MAP didnt cure, so now i have sent back Ignition Module and MAP in 48 hours. the plus side of having friends who own repair shops. cleaning the EGR tommorrow and changing the Knock sensor this week. im banking one or the other will finally fix this. (unless it comes down to replacing the EGR).

but on the bright side, i went ahead and got my smog today and it passed and my SES light never came on or threw a DLC during the test.

but still would like to be done with this occasional SES. i let you know.

[demon-hemi]

Re: Another SES question....

ill tell you it is not the EGR, i had the same problem on my 95 3.4l, and i put on a bran damn new one, i worked at chevy and had all their tools to monitor the car and it always read the egr solenoids 1-3 and even after trying 2 or 3 diff egr, my oly guess was the o2 sensor, but take it from me dont waste your mone on an egr like i did, it wont work.

p.s. mine would come on only if i went over 60 and then slowd back down below 60, never could understand that ****. . . .

[vallentinerocks]

Re: Another SES question....

Cleaned EGR and also had a gasket leak from the EGR post to the exhaust. (now i know where the exhaust sound was coming from, sounds better now). took it for a drive, in town under 50, SES did not come on. got on highway, up to 65, let it idle and coast and SES didnt come on the first few times. but..... yes it finally did. very intermittent but still throwing SES and sure the DLC is still 43.
when i get back to the shop to hook up scanner, sure it will be code 43 (reads knock sensor error).

So guess I will change knock sensor since its cheap, but a pain to get to, will have to put it up on the lift at the shop to access better.

but yeah, still the same ole problem that alot of us seem to have, looks very common. will let you know if new knock sensor fixes it. atleast its smogged now though.BTW, i am going to replace the O2S's just because, even though the counts and ranges are good. might as well, they are well overdue and see if my gas mileage improves.