RCFNN

installed a invidia q300 catback after 2 days im getting check engine light code p0430

has anyone else had this problem or could it just be an exhaust leak or bad 02 sensor?

05RollaXRS

It is most likely the same issue most likely that has been discussed extensively in the past. The wrong gaskets are installed. The front ones in the back and vice versa. That usually causes an exhaust leak. The size difference is very little so one has to be careful installing the correct one in the right place. I was very careful with my installer on this and have had zero issues over 2+ years.

RCFNN

i think the exhaust kit only came with 2 gaskets in the bag tho unless the gaskets are on the wrong way maybe?

RCFNN

RCFNN

Only came with those two gaskets in the picture

05RollaXRS

Yeah. there should be two like I said above. I am saying, they were installed incorrectly. They are very close in size so the front one is in the back and vice versa causing an exhaust leak.

LoSt180

There's 3" and 2.75" 2-bolt gaskets that come with this exhaust. The 3" goes at the front, and care must be taken to keep it centered when installed. If not, you'll have a leak that causes that code.

It's been documented and discussed a lot.

I wish Invidia would have used a 2.75" flange, then a regular oem round gasket would be perfect.

MCB1970

I just got a CEL yesterday coming home from work and I have the Invidia exhaust. I am assuming it is for an exhaust leak, but I could be wrong. I will find out this afternoon. This is my second CEL. The first gasket failed after about 6 months on my car and it was the original gasket that came with the Invidia. My mechanic ordered a bunch of gaskets to see which ones might fit the best and that is what he used the last time. I did buy the exhaust second-hand. I think the original owner said the exhaust was on his car for about 2000 miles or so. I drive about 15K a year and in Northeast Ohio winters. So maybe the gaskets will eventually fail if exposed to certain conditions even if installed correctly.

RCFNN

so i took the car back to get it checked out and they said everything was lined up correctly with the right sizes gaskets in the front and rear like i assumed they would say bc they prob didnt want to take it apart again. they said maybe a bad o2 sensor or try putting on L shaped o2 sensor extensions which might fix it. i cleared the code to see if it comes back on might have to take it to a more professional place here in cali to get it checked out

btw this exhaust is brand new and ive only driven it 150 miles so far

05RollaXRS

I have put on about 1500 miles on mine in the last 2.5 years and have had zero issues. Granted, mine is only driven in warm weather in the spring/summer.

RCFNN

they showed me the gaskets it did look like the bigger ones were in the front but i could only see the outside of the gasket they didnt take it apart to measure the inside diameter

GrizzlyMan

1500 in almost three yrs is very low clocked miles

05RollaXRS

Yeah, that is true. It has only 10,000 miles (and 5+ years old). It is my spring/summer/hobby type of car. I only drive it when I want to since I have two other cars for all of the daily work.

LoSt180

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.

SUNNYRCF

This is a very common issue and is caused by an exhaust leak where the headers attach to the new exhaust. It's pretty obvious which gaskets go where, but care needs to be taken to make sure the header surface is clean and flat and that the new gasket is lined up properly when the bolts are tightened. Unless they F'd up the O2 sensor, it's just a small leak. I installed this exhaust myself about 18 months and 5,00 miles ago and never had any issues.