2007 lexus is350 310k.

Hello guys I had holes In my old exhaust system so I had it replaced. The shop custom made it, magnaflow mufflers and cats. Only thing not new is the headers.

I was getting exhaust fumes with the old exhaust and I am still getting it from the new exhaust. Only seems to be there when I'm getting on the gas hard. I brought it back to the shop and they agreed they can smell it but could not figure
out the cause and advised that the headers r not leaking.

The pieces in the trunk that held relieve pressure when the windows closes are degraded however I duck taped them so I doubt that's the cause.

Does anyone else have any other advise?

 

You might not want to have the pressure vents duct taped. Search Google to find the DIY. Is the check engine light on for bad cats?

https://jalopnik.com/heres-what-thos...-re-1828016409

 

No check engine and brand new cats

 

The cats you are referring to is on the mid pipe?

The stock manifold cats are the one's that would create the strong smell you're experiencing. Rotten egg smell?

I'd get a scan tool to see how the fuel trims behaving. There could be a rich mixture going on.

 

I been preaching about this on my previous threads. Been trying to diagnose the egg smell. Its been my last 4 threads. DLR wants to charge like $4k to replace mid pipe cats and what ever contributes to the smell. One mechanic from Lexus said "yo its an IS250 get use to the performance car or get your self a different model type of Lexus. GS, ect." He suggest that most that have the egg smell have no diagnostic codes with scan tool, no problems at all but the smell. So its more of a cosmetic repair, so to say because he will take off Good CATS and the other related parts, and put new OEM parts. Then they gotta figure what to do with the old parts that are still actually good. Lexus recommends the whole assembly in that area to be changed in order to fix the issue.
Been using Shell Gasoline, but last week man the smell was so bad a cop had to roll up his window and give me the side eye.
I would take MikeFigs's advice above and start there.

2010 IS250 NO mods all STOCK
No major repairs.
134k still going strong

 

So I just talked to the shop. The secondary cats were removed the manifold ones were replaced

 

Did it solve the problem?

 

So this is what I've noticed. If I have just the drivers side window down it smells when I get on the throttle. If passenger and driver side down I can barley smell it. At this point I can probably just live with it by having the windows down