Well i raced an 03 M3 last night and as i was half way through third gear, i heard a big boom. Before this my exhaust has been raddling really bad for the past few days like never before. Now when i step on the gas, it sounds like an srt4!! It is soooo loud. I first thought my head gasket was done but tested it by revving the **** out of my car to see if the dipstick popped up by thankfully it didnt. From the sound of it, when i rev the engine it sounds like i have an open downpipe. No exhaust flow goes out the muffler at all. All the air flow is coming straight out of my downpipe or header. One of my friends told me i have a really bad exhaust leak. He thinks my gasket to my header or downpipe is busted which i agree with him. The car is really sluggish and doesn't accelerate as fast as before. I am gonna take the car in on monday hopefully and get it looked at. Any info would be great.

 

Sounds like the stock cat took a dump. Rip off the downpipe and flip it upside down. If the core comes out, that was you're issue. Also check to see if the flex part of the downpipe blew out. I think you just may have got lucky on this one.

 

Sounds like you blew you cat.

 

i hope or else i am screwed

I think i am going to order a downpipe. Any suggestions? I was thinking zzperformance.

 

ZZP or Cobalt Addiction. Either will get the job done.

 

Thanks man for your help

 

i blew a hanger once racing, sounded like metal hitting metal, thought it was the cat forsure, turns out one of my exhaust hangers was shredded, not sure how that happened, replaced it with a stronger one and its all good, in yer case if the car is runnin like ****, its probably the cat.

 

I use the Cobalt Addiction 2.5 High-Flo... and it works GREAT. I know some of the DP's people were complaining about hearing a whistling when they accelerate. I dunno if that was the case with the ZZP's or not... But i know Mine doesn't. I am very satisfied!

 

Bryan just get the pacesetter, and have them make the downpipe at the exhaust shop, its gonna cost you about 100dlls cheaper, I just dont see why you would spend 250 on a piece of pipe you could have made for 150.

 

All too true!

 

Same **** happened to me. I took it in and found out I had a leak in the connection over the axle and the mechanic replaced the gasket in the flange where the the exhaust bolts to the DP. However, I get a really bad rattle in the muffler at cold start up and the exhaust just not sounded the same since. What's differenct is that I am not having performance issues though. Sounds to me like something in the muffler is cooked. I'm going to find out about warranty on the exhaust.

 

No problem bro. I think we're all going to run into the cat clogging issue. I know it happened to me already right after I got my car running great again. I made my own downpipe with a vibrant cat and a mendral bend, but I have a welder so that helped a little bit.

 

Looks like i will buy the pacestter header and get a custom downpipe before you lol

 

what u mean, I just got my Pacesetter.

 

O i didnt even know lol Now i need to find an exhaust shop to hook me up. Hey the weekend after this one coming up you wanna install the 60's and 2.6?

 

so i got my header installed today with a downpipe and the part that broke was the flex joint. We took the stock downpipe off and the flex joint was shattered (hints the rrattling noise from my exhaust). But the header looks really good with the downpipe. Ill update and tell you guys how it turns out when i drive it for a bit.

 

o and the guy that is installing all my stuff is going to make a cataback and downpipe for our cars. The catback he said would be around 400. the downpipe hes not sure yet but around 225ish. If anyone is interested. He's a professional

 

Cant wait to hear ur results man!

 

It looks and sounds.....

Your gonna love it man!!

 

This happened to me and my exhaust note completely changed to where it sounded like a WRX and I was over boosting with a huge lose in power, but it wasn't my cat! Turns out 2 lifters failed so I was running on only 14 valves!