EGR epic failure.

[tkoforpresident]

so some of you know i was getting the dreaded SES light that comes on when decelarating from over 55mph. This is usually associated with the EGR not working, whether it be the valve itself or the computer not turning it on or an acutal physical restriction in the tubing itself.

well, i recently replaced the EGR valve with a new remanned one and the code still did not go away so i forgot about it for a little bit. then i read up on a few threads about how you can test to see if your plenum is clogged by unhooking the egr tube at the plenum and turning the car on. apparently if there is no vacuum leak then it is clogged.

well, a while back i was doing plugs and wires etc. and i took off the whole egr assembly. so there was no egr on the header pedastal or hooked up to the plenum, both holes were wide open though i didnt know it at the time.

i started up my car and it ran perfectly fine, idled right at about 1000 rpm in park. much to my surprise when i looked in my engine bay the EGR hadn't been attached yet!

now am i correct in believe that there should have been a MASSIVE vaccum leak considering the whole EGR assembly was removed?

and more importantly does this mean i have a clog in the plenum that is keeping the EGR from functioning?

i hope this is the key to getting this problem fixed.

thanks

max

[3.4 slow to go]

Re: EGR epic failure.

nothing on the header or intake? should've ran like **** (if at all) & had MASSIVE exhaust leak.

[tkoforpresident]

Re: EGR epic failure.

nothing on the header or intake? should've ran like **** (if at all) & had MASSIVE exhaust leak.

well i'm sure it did have a massive exhaust leak, but i didn't drive it i just let it idle.

still should have had a HUGE vaccuum leak right?

[PaganEgyptian]

Re: EGR epic failure.

yes and no. My EGR is just a decoration now. I turned it off in the PCM program. Any decent tuning software can turn it off. Try running Sea Foam. Thats the best thing I can think of, and by letting it soak over night after you stall it out with it.

[tkoforpresident]

Re: EGR epic failure.

yes and no. My EGR is just a decoration now. I turned it off in the PCM program. Any decent tuning software can turn it off. Try running Sea Foam. Thats the best thing I can think of, and by letting it soak over night after you stall it out with it.

theres no tuning that i know of for the 3.4 that can delete the egr from the pcm.

do you think the hole is physically clogged up?

[jrocstar]

Re: EGR epic failure.

you would still have a massive exhaust leak and it would run like ***. how about checking to see if it is clogged. i don't know maybe crazy idea but if you see carbon behind your throttle body or under the egr plate probably is clogged. or you can start it and hold your finger over both ports this will let you know you have exhaust flow to and from the egr but beware this is not end all you can still receive a insufficent flow code from partial blockage that this test will not make clear. and they make egr simulators

[97rs4life]

Re: EGR epic failure.

there is not going to be a massive vacuum leak as the egr valve is meant to open and close depending on your driving. So it is suppose to let air in at times.

There are people that unhook the egr from the exhaust side and just put a little filter on the end to suck in fresh air. Works fine

Make sure to get a block off plate though for the exhaust manifold as that is one big leak

[tkoforpresident]

Re: EGR epic failure.

there is not going to be a massive vacuum leak as the egr valve is meant to open and close depending on your driving. So it is suppose to let air in at times.

There are people that unhook the egr from the exhaust side and just put a little filter on the end to suck in fresh air. Works fine

Make sure to get a block off plate though for the exhaust manifold as that is one big leak

ah i see, so it might not be physically jammed then, since it's supposed to open only at certain times.

someone suggested my pcm might be wack, what do u think?

[97rs4life]

Re: EGR epic failure.

personally I think your car is whack and needs to be replaced with a newer fbody. You have had too much crap with this one. I have not heard of anyone with a pcm causing their egr to mess up

[Firebirdkid96]

Re: EGR epic failure.

oh snap

[jrocstar]

Re: EGR epic failure.

i guess i am too stuck on the 3.8 but on a 3.8 car the maf is before the egr so any unmetered air would cause issues and you would n ot be able to just put a filter there. even without a maf it is still accelerated air higher than stock idle air tables. egr is justg a pintle and seat blocking ehxaust from intake. if you remove you have a open intake and open exhaust sounds like a massive vacuum leak and a massive exhaust leak to me if it was a 3.8 i clould say for sure so you probably should stop having all these stupid issues and buy a newer f body maybe with a ls1 so you don't even have to mess with a egr

[landj]

Re: EGR epic failure.

Who's buying LS1's for everyone? Sign me up! I want one too!

[tkoforpresident]

Re: EGR epic failure.

problem found:

bottom of the plenum there is a passage from the EGR to let air into the front of the upper intake. this was a clogged with carbon, i mean solid. so basically when the EGR does try to function, it recognizes that none of the exhaust gasses its trying to recirculate are even getting into the plenum and throws all 3 EGR codes. by cleaning out that passage with a long wire brush and carb cleaner, the codes should go away (if your EGR is in working cond. that is ) I don't know how it is on the 3.8 or other engines but this long, tiny passage under the plenum is very succeptible to being clogged by carbon. either way, this is why most of our EGR's fail on the 3.4

[flamingchicken]

Re: EGR epic failure.

3.8 is like a dump, no passage. but there are plenty of threads about the egr passage being clogged on the 3.4, as much as i see you around here i figured you woulda seen one.

[tkoforpresident]

Re: EGR epic failure.

3.8 is like a dump, no passage. but there are plenty of threads about the egr passage being clogged on the 3.4, as much as i see you around here i figured you woulda seen one.

i did, i was just wrapping up this thread so anyone who reads this in the future can figure it out. :tup: