Can a exhaust leak cause your engine to loose power? I had a leak where the cat meets the "B" pipe, so I re welded those two pieces. My car feels like I gained 5 hp, also my exhaust got quieter.

 

Bump. I want to know too i think i have one

 

I had a nasty exhaust leak between my y-pipe and cat a few years ago. I fixed the leak and went from running 15.0's to 14.8's.

 

It might also cause your O2 sensors to clog up because the car would be running too rich when there's an exhaust leak...

Later

 

in addition, ur gas mileage will get better due to less leackage, less-richer gas. ECU will adjust its settin after u fix ur leackage.

 

Yes you will definately loose hp with a leak

 

Just adding to most of these comments, any exhaust is going to hurt performance. Nothing too signifigant depending on where it is, but a loss none the less. I had a leak in both my exhaust manifold and old Y-Pipe.

 

i had a busted flex section and a missing bolt between the y pipe and the cat.. lets just say i had NO POWER...

i just replaced my y pipe and got new bolts.. man the car is quieter and pulls hard

 

Cool, thanks for all of your comments.

 

How does a cutout gain HP? That's a HUGE exhaust leak.

 

Between 1500 and 2500 rpm under some load, I hear a really high pitched whistling noise from my exhaust. I *highly* doubt it's my intake. Maybe I have a pinhole leak and it's making a sound. Gotta get a look at it

 

It depends on where the leak is. If the leak is close to one of the o2 sensors, then air entering the exhaust during reversion is sensed by the o2 sensor and the ecu thinks the engine is running lean, causing it to richen the afr with a subsequent loss of power. A leak far enough back won't adversely affect performance. If the leak is large enough to reduce back pressure at high rpm (e.g. a cutout), then your performance may improve, depending on how restrictive your muffler is in the first place.

 

well here is my experience. i took a run down a dragway last month. i jerked the car hard in second and felt a shake and continued on down the track. coming up for my slip i noticed the car sounded way different. i got to thinking O NO ! what have i done ? I looked around, waited a while and continued doing runs. The car also continued to sound out of whack.

I got several 15.2 times and then left the track. The noise still bugged me so I reved and listend to the car and it sounded like more exhaust noise coming from up under the car than normal.

Went to my exhaust guy the following day and sure enough, I had an exhaust leak. i had blown a gasket in between my test pipe and b pipe. it was all burnt up, and shot and things were a bit loose.

Convinced that my car could do much better in the 1/4 mile minus the exhaust leak. I went back down to the track expecting a much better performance.

My findings were really nothing. My MPH was up ! Running around 93 mph in the 1/4 mile consistently but my best time was 15.1. So the car was making good power but I didnt see much difference in times. So I thought ...hmmm, my exhaust leak didnt make as much of an impact as i had thought ..and its always a guessing game with me. i have no mechincal knowledge ...but anyways thats something that happened to me with regards to an exhaust leak

 

I have a nasty exhaust leak at the b-pipe and cat. I need a new gasket I guess. BuZZZZZZZZZZZZZZZZZZZZ

 

I have a leak from my flex section of my y-pipe and the car feels like a dog....

 

I have at least one leak that i know of, right behind my muffler, from my accident...



Eric

 

Yeah, I know a leak in the flex section of a Ypipe or in the exhaust manifold is BAD since it's so close to the 02 sensor. My setup right now is Y, testpipe, stock Bpipe, and straight thru muffler that is getting on my nerves FINALLY after 6 months of driving this way. I'm tired of being like all the Civics around town with a loud exhaust. So, I'm going with this setup... Y, testpipe, QTEC, stock Bpipe, stock muffler. I can once again be quiet on the streets. And I will still have a slight exhaust note with my stock muffler. Which is ok.