Just as the question asks.what would be a better Egr valve to use with headers? I need to replace mine due to it causing a good pinging problem and the wonderful code 32 issue.I know there is a differance between negative and postive valves.Does anybody know?

This is an educated guess on my part, but a negative backpressure (BP) may be best. In this case as back pressure increases the valve will close. A positive BP valve needs BP to open. With headers and a decent exhaust there may not be enough BP to open it.

Where a negative BP valve will still open.

RBob.

i believe RBob is right, a negative back pressure valve would be better with headers than a positive valve would be.
but, in my opinion a non-back pressure valve would be the best bet.

as far a i know, you can tell the difference between the types of EGR valves by looking at the end of the part number, a positive valve has a P on the end of the number & a negative has a N on the end. something like 17084582 P would be a positive back pressure valve. this may not apply to aftermarket valves.
with the valve off the motor, if you appy vacuum to the valve & it opens, then it is a non-back pressure valve.

non back pressure would be positive right?

There are 3 types of valves: negative BP, positive BP, and non-back pressure.

The non-back pressure will just open and close according to the applied vacuum.

RBob.

Well I tried to get a new egr valve from autozone and I gave them a negative egr valve number Rochester 17088125. The one that's already on the car.They sent me a positive egr valve WELLS EGR132. It says on the paper that the valve came with that if you use the appropiate orifice washer in the valve that it will act as a Negative egr valve. Is this correct?

the orifice washer controls how much the EGR valve will flow, it doesn't make any changes to the valve being a negative or positive back pressure.

if i can find my exploded views of what makes an EGR valve a back pressure or non- back pressure valve i'll post it up.


on a side note, i personally don't like Wells parts, i have had too many problems with them.

Use a Negative backpressure valve. With Edelbrock headers, high flow cat, and hooker cat back exhaust i was having CODE32 problems. Went from a positive valve to a negative valve from a TBI truck and it works like a charm.

I'm bringing this one back due to the fact I can't stop this damn pinging.Where can I find a negative backpressure valve? I have looked every where and every parts store in town only carries positive valves.This is driving me nuts.I have even tried the chevy store here in town and they say the part number I have given them isn't a real number(17088125 N) so I have no clue as what to do now. I don't want to blow up my freaking engine from detenation.

Well I'm hoping I found the right EGR valve i was given a new number by a different dealer in phoenix 17113496.I ordered it today.I guess if all else fails I just gave Brian at Tbichips a call to see what it would cost to burn me a chip without EGR.He said he could burn it for 50 bucks.It's cheaper than a new valve so lets's see what happens.

sorry to resurrect this dead thread, but could you let us know which egr you ended up using (if you are using one at all xD) and which part# it has?
i just couldn't find other threads with sufficient information.
thanks

I too would like to know what egr ended up working

Let us know

Thanks

Honestly I got a chip from tbichips to delete it out. No matter what I did with ANY EGR valve I get rid of the code 32. So I gave up and put in a block off plate.

mmh, that's too bad i intended to keep egr to save some gas.. i think egr is a quite promising system for fuel economy at least.

anyone has egr + headers running?
maybe RBob could chime in here, i know that the EBL has some nice tables and settings for the egr.

thanks

hey, to the ones still waiting on a reply on this and can't quite figure out which egr valve to use, i contacted RBob about this and that's what he replied:

i looked up the part number and all i came up with so far was an LT1 EGR valve for the 94-97 years.. anyone else?

I don't know the number BUT the stock EGR for a 91-93 350 (LTZ)
caprice works great. I'll try to get the part number later.

hey, i just got another reply by RBob on this:
but then, this one was the one already tried by robertfrank wasn't it? i even found this to actually be the original 305 tbi egr valve on some sites..

The stock one is working fine for me.