P2097 Code set today

[Brian20]

Got a code today for a P2097 Post catalyst fuel trim system too rich bank 1. Owned this car for over a year now and have never seen this one til now. A year ago, I had the P0420 and replaced the catalytic converter along with both upstream and downstream O2 sensors with genuine Denso sensors and never had an issue since. It got real cold here in the past week and that is when this code happened. I am kind of leaning towards a new mass air flow sensor, since this is a rich fuel code and seems to be air temp related, and that would make sense for the mass air flow sensor I think....anyone else experience this P2097 code and if so, what did you do to remedy it?

[Samus]

Got a code today for a P2097 Post catalyst fuel trim system too rich bank 1. Owned this car for over a year now and have never seen this one til now. A year ago, I had the P0420 and replaced the catalytic converter along with both upstream and downstream O2 sensors with genuine Denso sensors and never had an issue since. It got real cold here in the past week and that is when this code happened. I am kind of leaning towards a new mass air flow sensor, since this is a rich fuel code and seems to be air temp related, and that would make sense for the mass air flow sensor I think....anyone else experience this P2097 code and if so, what did you do to remedy it?

Good call on the maf sensor. I also think that is the culprit. Condensation might have popped the code as a drastic change in temp can cause that.

Try removing it and cleaning it.

Second thing to check is your injectors. Maybe one of them is leaking freely. Any gas smell around the engine bay?

[Brian20]

Just an update, a new Denso MAF sensor seems to have fixed the issue. The code is no longer popping up, and it is not in the pending codes either. Of course, the temps here have come up a good 20 degF in the past few days, so we will see when the real winter returns if the code is truly gone or not. Car seems to be running fine, just as it did when the code first presented itself. Will update if anything changes.

[Brian20]

Another update , p2097 popped up again today. Boo.

[Brian20]

Hooked up a shop vac to the tailpipe, set it to blower mode, started spraying some soapy water on all the exhaust joints, and found a pretty sizable exhaust leak, right ahead of the upstream o2 sensor which I now assume is causing the issue I'm having. It's part of the exhaust manifold, where all 4 cylinder exhaust pipe merge into one flange, right where the cat bolts to. Pretty unreal how much air was coming out of it and how much of a vacuum it must produce when the engine is running as there was no soot anywhere to be found. I tried the cheap way and bought some exhaust sealant paste and painted around all the crevices in that exhaust collector, but no luck as after it dried and I went for a test run, the fuel trims when down a little, but when I came back and retested for leaks, lots of bubbles still appeared in the same spots. Next step will get some new gaskets on order, remove the exhaust manifold, and try to weld the gaps closed from the inside. Interestingly enough, I ran some high grade BG 44K fuel system cleaner through the car a month ago and I'm guessing it removed the carbon build up on this exhaust manifold collector and caused the leaks to appear...so much for preventative maintenance...Ha!!!
Once I get all the one time use exhaust gaskets in this week, I will tear into it next weekend and post back and update. I'm just really surprised this has not been more of an issue for all the cars that have had this 2.0 J20A engine over the years. Seems like this engine code is really rare. Lucky me.

[GhettoFunkRadio]

Interesting find and good luck with the repair!

[Brian20]

Exhaust manifold is beyond repair. Looking for a used one if anyone has a lead on one. Thanks.

[Brian20]

Ok, final fix worked. I replaced the exhaust manifold with a salvage yard part, much lower miles then my car, and the code is gone after alot of driving. Fuel trims are back to being normal. Fuel mileage has increased substantially.

[GhettoFunkRadio]

Ok, final fix worked. I replaced the exhaust manifold with a salvage yard part, much lower miles then my car, and the code is gone after alot of driving. Fuel trims are back to being normal. Fuel mileage has increased substantially.

Out of curiosity, what sort of mileage were you getting at its worst?

[Brian20]

Out of curiosity, what sort of mileage were you getting at its worst?

Was getting around 19mpg in town driving, now getting around 24mpg in town.