I had been gearing up for the dreaded cat/flex pipe replacement for a while now. I had the usual O2 sensor CEL codes forever and was just getting every last mile out of them and the cats. The last couple of weeks was the closer as exhaust leak was getting louder and louder. Both flex pipes finally gave up. With summer coming I figured now is the time.

I am pleased to say the original pipes/cats lasted 215k miles. Replaced both sides and all 4 O2 sensors. Back to perfection. Only thing left in the not-to-distant future is the 3rd timing belt change. Last one was at 168k (basically 85k each time). The previous owner was as **** as me and took EXTREMELY good care of this car. He got 85k miles out of each belt.

However I am going to shorten the interval of timing belt to 60k then replace. Both times it got the routine belt, tensioner, water pump, seals etc. Will be the same this round. I am targeting 230k then get it done.

I love my A4.

 

Glad to hear man, too many people neglect stuff like that.

 

Now I have a P1128 CEL. Trying to narrow down if it is the new O2 sensor or a vacuum leak. Never ends! However it could be from me pulling open one of the vac lines to make sure it had vacuum - which it did. I did this after pulling the battery, allowing the car to sit for an hour and doing a throttle adaptation. I figured letting the car remap itself and a new zero point would be good for it.

I was checking vacuum just for the heck of it to make sure it had vacuum. When I started it up after everything it ran rough for like 2 seconds then leveled out back to normal. Maybe it took a second for the vac lines to calibrate? Then after that I drove to work and got the p1128. I cleared it out hoping it was just my restart. Time will tell. All vac lines were replaced last year. Maybe there as broken one I can't see. Chasin' gremlins.

 

After hearing what I thought was a leak in the pipes, then checking the gasket connection of the pipes to the manifold, it was discovered that the gaskets that came with the pipes were not the correct ones. Which is odd because the pipes were OEM. So the Indy got in the right ones. Put them on and the sound was perfect and no CEL.

I am celebrating this victory today and enjoying no CEL since a week after I got the car. The car was purchased knowing new cats were coming soon (as they were originals) and I got almost a year out of them. Didn't need an inspection until next year so I rode them out until they literally fell apart. All is well.... for now...