Test pipes seem like the ultimate exhaust option in the fight to reduce back pressure. But there are questions...

Recently two people have noticed excessive oil use after installing test pipes. Can this possibly be connected? It seems to be because one of the people removed his test pipes and the excessive oil use stopped.

Additionally people mention the possibility of a CEL light coming on if you remove the cats and install test pipes. What is a CEL light? I looked in the 2005 Coupe Service Manual and the Owners Manual and couldn't find the first mention of a CEL light or error display.

I believe the sensor that threads into the cats is an Oxygen sensor. I was not able to find any info on the Cats in the Service Manual either. People mention using anti-foulers on the Oxygen Sensors to remove the CEL errors. What does this actually do? I've heard of anti-foulers for spark plugs, but not for Oxygen sensors. In the old days, anti-foulers kept oil from getting on spark plugs in a worn engine, or one with a broken ring, etc...

 

Hey man -

CEL stands for Check Engine Light

Foulers are used to space the O2 sensors out from the exhaust stream so they don't sniff so much - then the errors wont occurr. Without CATS, more gases flow, as they aren't burned, and the O2 sensors will sens that and throw a code. If you space them back, and not let them breath it all in, you fool them.

That's the purpose in this case.

I have not heard of oil burning from the use of testpipes, more than I heard of less gas mileage from the heavier use ofthe gas pedal in relation the better performance and sound that results after their installation.

Come to think of it...oil burning could be attibuted to harsher driving habits as well.

Rick

 

OK, I officially feel like a dummy... I'd be embarrased to tell you how long I looked for that...

Interesting. I thought the excessive unburned gasses might be contaminating the O2 probe, but it's a completely different situation. We're always trying to fool the ECU. I like the old days when I could turn the distributor, change the jets, and read the plugs.

So, hypothetically, what is your optinion on test pipes? I mean if someone had a car just like your Z, any idea how they would work? You've probably invested more time and money in street exhaust than anyone I know, so I value your opinion. You don't have to answer if you don't want to.

This is exactly what I thought of when a friend first posted about excessive oil use on our forum. But, when I read the second post from the fellow in this forum, and he said the problem went away after he removed his test pipes, I was astonished. I personally find it difficult to believe that reduced backpressure can cause an engine to use more oil... that's why I'm asking.

I suspect there are lots of people that read this forum and have test pipes. I hope some of them will chime in and tell us about their experiences.

 

Hell no if this motor burns oil for being driven just as hard with test pipes this motor is a big POS. I drove it just as hard with stock cats, so that point is null and kind of a smart *** comment. For as much oil as I was burning it would have had to been sucking oil in through the PCV system due to not enough back pressure or a collapsed oil ring. A valve seal would not have been burning that much oil and it would have been puffing blue all the time. I was getting blue blowing out under acceleration. So PCV system or oil ring and since it has stopped with stock cats in it isn't an oil ring. And the PCV system is fine, so I am guess it was the test pipes.

I was the one with Strup test pipes who was burning oil. I have since taken them off and not a single drop of oil has been burnt since that time. I did a fresh oil change and new filter just before I started the car up after swapping the stock cats back in place. I was burning about 1qt in 250kms. So far I have driven over 300kms with stock cats and like I said not a drop of oil. No more blue being blown out the tailpipes, no smell, nothing.

 

CEL is actually the SES (service engine soon) light in the dash, same thing.

As far as oil burning??? I've had my test pipes on for over 20k miles and no oil burning.

the non-fouling adapter is actually the one used for spark plugs, I had the SES light come on after I installed the test pipes. I installed the adapter and light hasn't come on in over 10k miles. If you have a 2004.5 or later it's needed or you'll get the SES light.

 

i dont think i have this problem.
but that could be due to the fact that i have an 03 which can run test pipes without throwing a cel light.

the cel light comes into play with people that have 04.5 and newer g's. this is because of the higher emissions on the car. i think its called ulev2 or something like that. where my car is a ulev1 so it doesnt have the problem.

it seems that this burning oil problem is all on newer g's. serengetti what year is your car. im goin to assume that its an 05 because the seregetti color wasnt available until then.

 

Well -

I've got an 05 - headers, testpipes and all, and much much more - not a single drop of oil burned - 16,000 miles - maybe it's just your car???

I haven't heard of the issue until just now though, and my pipes have been on for about 12,000 miles...

Maybe your car is a Friday build - then again you don't seem to have a sense of humor much, so I take that back!

BTW - Not quite sure why you had to go off with the attitude the way you did...my comments were not smart ***** as you put them. Many people tend to go much harder on their cars when they mod them and wonder why things start going wrong suddenly...it was a valid comment.

Rick

 

I have resonated test pipes on an 03.5 for over 10K miles and no oil burning at all. I did get a SES code right away though. I think it was due to the Testpipe/Stillen catback combination to increase flow that made it throw the light.

Did the no-fouler trick, reset the ECU, and no light since. I also wrapped them with hi-temp header wrap to quiet them down some more. Worked nicely.

Still suggest getting resonated because it is likely you will get some rasp w/ the non-resonated and you will definitely get a code with any of them. You need to do some stuff to live with TP's on a street car, but the gains are worth it though, no doubt about that. The motor revs much more freely without those "plugs" in the way.

 

Sounds like a bad install. Something was routed wrong with the PCV loop etc. Either that or his motor is fubar and the cats are just scrubbing the blue that is still there

 

if you have an 03.5 you shouldnt have to do the no fouler. 03, 03.5, and 04 have the old emission standars in them so they can run test pipes its the new emissions that started ont eh 04.5 that cause the problems with test pipes.

i have gutted rt cats and i havent had any cel lights yet

 

And what's the EGR setup like on the VQ? Could have been hooked up backwards or something siphoning oil from the intake. I think he had the the intake spacer installed and took it off at the same time as the testpipes. Putting the stock intake back probably fixed things, not the cats.

 

I got a SES light within 5 minutes on my 03.5, but the car ran great and no indication of any problems. Just irritating to look at and not knowing if there was a real problem prompted the no-fouler fix.

 

I apologize, but it seemed like a smart *** remark. I don't see how it was a bad install either. My brother and dad did them and they have built motors, done engine swaps in S-10, done headers and exhaust on their Cobra's etc. So that wasn't it. Everyone that isn't having problems is running pre 05 models. I have an 05. Maybe it isn't your test pipes that cause the problems, but maybe the Strups are fubared?

 

Never even received the headers yet, so I haven't touched the EGR valve. The intake(MREV+) was on the car for over 8000kms before the test pipes went on and no issues what so ever. The intake runners had zero oil in them. Now it could have been getting sucked through the PCV system, but we checked the PCV valve(sucked on it and tried blowing in it) and it is functioning properly.

 

Motor isn't fubared. Like I said I was checking the dipstick besides noticing the blue oil smoke out the back. Dipstick would be full leaving my house, go for a nice drive around 200-300kms and come home. Let the car sit over night and come out and see the dipstick down at least half to a full quart. So no the cats are not scrubbing the oil out of the exhaust.

The dipstick now stays to the full line and has not dropped since I reinstalled the stock cats. And to prove to you I am not lying and the MREV is not the problem I will be putting the MREV back on as soon as I get back from the dealership next week. You can think my brother and dad are idiots all you want and installed something wrong, but I guarantee you they can work in a garage so I trust them not to install something wrong. My dad has been a certified mechanic for over 30 years.