invidia q300 catback install getting check engine light code p0430
Intermediate
Joined: Aug 2020
Posts: 278
Likes: 152
From: Nh
It's 100% an exhaust leak and they just didn't want to take it apart. Only way you can have a failed sensor is if they weren't careful during install and really twisted the wires to the point one broke. The only reason you would need the L-shaped extension is if you have headers installed.
I went thru this when the guy who installed my headers stuck the smaller 2.75" gasket on the front and triggered leaks immediately. I think I ended up getting another smaller thin round gasket and stacked the 3" one on top with the use of copper RTV.
The problem is that the OEM manifold (as well as PPE headers) have a recess for the stock round gasket. The 3" flange on the Invidia exhaust doesn't always exactly seal with the stock gasket, mainly because the outer diameter of that gasket is only a hair over 3". If you (or the shop) used the 2.75" gasket at the front, it deforms causing a leak also. The 3" gasket will sit with the Invidia flange pretty well, but care MUST be taken to keep the gasket centered as the exhaust bolts are tightened up. There's too much slop in that style gasket to just slap in on, tighten bolts up, and expect a good seal. I made a quick video on the Facebook group page showing the gasket issues, might find it and stick it on YouTube for everyone else.
I went thru this when the guy who installed my headers stuck the smaller 2.75" gasket on the front and triggered leaks immediately. I think I ended up getting another smaller thin round gasket and stacked the 3" one on top with the use of copper RTV.
The problem is that the OEM manifold (as well as PPE headers) have a recess for the stock round gasket. The 3" flange on the Invidia exhaust doesn't always exactly seal with the stock gasket, mainly because the outer diameter of that gasket is only a hair over 3". If you (or the shop) used the 2.75" gasket at the front, it deforms causing a leak also. The 3" gasket will sit with the Invidia flange pretty well, but care MUST be taken to keep the gasket centered as the exhaust bolts are tightened up. There's too much slop in that style gasket to just slap in on, tighten bolts up, and expect a good seal. I made a quick video on the Facebook group page showing the gasket issues, might find it and stick it on YouTube for everyone else.
Intermediate
Joined: Aug 2020
Posts: 278
Likes: 152
From: Nh
When did you get yours? I’ve been waiting for mine for months because they are sold out everywhere. I hope this means mine will be here for summer.
Thread Starter
Driver
Joined: Jul 2020
Posts: 66
Likes: 8
From: CA
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Racer
Joined: Nov 2007
Posts: 1,308
Likes: 558
From: cali
I get that on my previous cars I’ve modded.
it’s called loving the sound and hitting the accelerator a little heavier than usual. It doesn’t help we have a V8 and it worsens the situation. lol
8th Gear
Joined: Jan 2024
Posts: 8
Likes: 0
From: OK
2020 RCF CEL after Invidia Q300 Install
So I know there's a lot out there about this, but a lot of it is older so I thought I'd post just to see. Put a Invidia exhaust on the car....immediately kept getting CEL for O2 sensor. Figured probably an exhaust leak or improper installation after reading everything on here so I had the exhaust guy install Grimmspeed extra thick gaskets after reading someone's post about this. The CEL went away for about a week and now is back on. I assumed it had to be something under warranty so I took it to the dealership....they're saying it's bank 1 sensor 2 that's damaged & needs replacement. I have the feeling this isn't going to fix the CEL so I was wondering if anyone had part numbers/possible link to purchase 1 or 2 O2 sensor fouler spacers...? And does anyone have any experience using these? Did it fix the problem or ? Thanks so much in advance...really appreciate it!
Pit Crew
Joined: Dec 2017
Posts: 147
Likes: 55
From: FL
It’s not bad sensor. It’s a bad sensor reading from a leak. I could never get mine to seal. 3 options:
1: Deal with it. I left an OBD2 scan plugged in and cleared the code as it came up.
2. Ditch it
3. Fiddle with the gaskets and sealant.
1: Deal with it. I left an OBD2 scan plugged in and cleared the code as it came up.
2. Ditch it
3. Fiddle with the gaskets and sealant.
Instructor
Joined: Oct 2019
Posts: 842
Likes: 717
From: MD
Depends on the specific code. It's certainly possible (and fairly easy) the O2 sensor wires got damaged when reinstalling back into the exhaust. A sloppy installer would fail to spin the wires backward before installing, causing tightly wound wires. If the O2 sensor wires look tightly twisted, then it might actually be damaged. If they look fine, then might just need to revisit my gasket thread and add some copper sealant.
Pit Crew
Joined: Oct 2018
Posts: 124
Likes: 40
From: Ohio
