Pat-Man

iTrader: (3)

Hey guys,

New to the board...I have had a sputter on my car (exhaust leak) and thought it was on O2 sensor for the longest time. What finally got me to get underneath the car and really look this time was that I started my car today while it was still hot and it was having trouble idling (around 350RPMs). Well, I waited a bit and it finally started to idle normally but I noticed that the leak noise was a lot more prominate. So, I jacked the car up and listened to the
noise. It sounded as if it was coming from the driver's side manifold. I got underneath the car and low and behold I found the leak. There are some pics to let you all know what I'm talking about. My question is, would this exhaust leak cause the erradict idle? I did port and descreen my MAF about two months ago...haven't had any trouble with it...do you think that might be it? or a combonation of the two? Thanks for any information you all might have. - Pat

DaddySS

An exhaust leak in front of the cat like that will definitely cause problems.

BTW, that should be covered under warranty - emissions parts are 5/50 I think.

Phate

iTrader: (2)

Yeah, it would totally screw up idle and part-throttle if it is upstream (or even close downstream) of one of the front o2 sensors.

Pat-Man

iTrader: (3)

Cool...that is what I thought. Thanks for the replies guys. I guess that would also explain when I had my cutout closed, I noticed that around 4500RPMs and up on WOT, the exhaust would start to sputter...as if my engine was cutting out (even though I felt no loss of power). I was hoping that I could let this slide until I get my headers and off road y-pipe, but it looks like it is getting worse. Thanks again for the fast replies. - Pat

LS1 Brent

I'm just curious but how can an exhaust leak be so bad? Please explain for me. Thanx

Pat-Man

iTrader: (3)

Well, from what I know, if it is that far up stream (especially so near an O2 sensor) it can introduce outside air into the exhaust stream giving the O2 sensors false readings which in turn can richen or lean up your A/F ratios. This can cause loss of power and even timing changes as the computer tries to relearn and adjust to the new readings. It is bad in my case because one of the main 02 sensors (the main ones in the LS1, right before the cats, are the ones that help determine your A/F ratios) is several inches away from this crack that I have in the cat flange. I think the crack got big enough that it started to send false readings to my O2 sensor which in turn caused my erradic idle (computer trying to relearn). I hope that doesn't confuse you. I'm hoping I can sit this out for a little while until I get my long tube headers. I would hate to have to pay more money on an exhaust system that I am getting rid of as my detuctible for my extended warranty is $100. - Pat

LS1 Brent

Thanx Pat. It did clear things up for me.

42NightZ28

looks like its time for some headers!

Pat-Man

iTrader: (3)

Yeah...that is what I am saving up for right now. So, the Lingenfelter cam is going to wait until I get the LTs and ORY pipe in...just wish I could win the lottery.... - Pat