[Bullytitan]

I recently did headers and cats on my 05' titan. I had a shop do the cats and connecting pipes and there is still a leak. I'm not sure where the leak is if it's at the headers or where they connected the cats. But I was just driving down the street and my truck backfired. Could an exhaust leak caused a backfire? Or maybe my AFR's are off? If anybody can help me as to why I am having issues with it's backfiring please let me know.

 

[JohnnyMac]

Exhaust leak definitely causes backfires. Usually only when you have let off the gas. The backpressure sucks fresh air into the leak and ignites in the exhaust pipe.

I've heard of folks attaching a shop vac to the exhaust and then blow air into the exhaust, then spray soapy water on the exhaust and look for bubbles.

 

[Bullytitan]

I was decelerating for sure. From your description it sounds like the leak is at the headers? Do you think thats accurate?

 

[JohnnyMac]

Hard to say for sure, but usually the popping and backfiring comes from leaks that are farther upstream rather than down towards to end of the exhaust pipe. I would try the vacuum thing to pinpoint it.

 

[Bullytitan]

Thanks johnnymac
You were right, it was further up than thought before! I actually got back up under the truck and tightened up the header nuts and then took the truck back to Pro Muffler and they re-did the whole downpipe and cat system! Now there is no leak!!

 

[Bullytitan]

Here are a couple pics of the work they did

 

[JohnnyMac]

Great to hear! Looks good!