Exhaust Fumes in Cabin at Idle/Stop

Hi Friends - me again with an issue with my newly acquired 2002 Accord.

At idle and while at a stop, the cabin receives a heavy dose of exhaust fumes (nope, not from the auto in front of me - I’m often alone at stop lights/signs)…any ideas for the most likely culprit?

This did not seem to occur until AFTER I had the timing belt (package) replaced…coincidence? Any feedback is greatly appreciated! Cheers!

Exhaust manifold gaskets, possible rust hole in exhaust pipe or flex pipe, or leaking EGR gaskets or pipe.

Exhaust manifold flange gaskets are a possibility

I can’t think of any reason why the exhaust needs to be messed around with during a timing belt job . . . so it might be a coincidence

My advice is to make sure the flange gasket hardware is tight

Make sure the exhaust manifold hardware is tight also, for that matter

Here’s another idea. Maybe it isn’t exhaust fumes; maybe it is from an oil leak, dripping oil onto something hot, which vaporizes the oil, then the oil vapor gets drawn into the passenger compartment through the windows or air vents. The reason I say this is that timing belt jobs often require removing the valve covers. It may be that the tech didn’t install new gaskets, or didn’t RTV the necessary points (per the service manual) during the valve cover re-install.

All of the aforementioned are possibilities.

But I urge you, PLEASE get this looked at ASAP!
If you have an exhaust system leak and carbon monoxide is getting into the passenger cabin, your life is at risk. CO is tasteless and odorless, if displaces oxygen in the blood, and it will put you to sleep without your realizing that it’s happening. You may just wake up dead. Until you get it looked at, I urge you to drive with a window open, or all of them open a inch or two.

Thanks all…given the ‘worst case scenario’ what are we talkin’ price-wise (+/-20%)? I’m simply guessing, but everything now-a-days seems to run between $350 and $500. I appreciate the valuable feedback you’ve already provided!!

By the way…I do have a life insurance policy for such occasions…@the same mountainbike, I love your comment ‘you’ll wake up dead’!! Bit of dark humor…I’ll keep my windows peeled a bit until this issue is squared-away!

Wise move.
$350 to $500 is probably a good expectation. You understand, of course, that it depends what they find. Flex pipes and cat converters can get expensive.

If it is just the valve cover gaskets leaking oil, that won’t cost much to fix. $100 maybe.

Thanks ‘the same mountainbike’ and GeorgeSanJose!! I’ll save my shekels for the repair!