Code 228

[Sajk]

Hi guys, any ideas on this? Dme is removing fuel but only for bank 2. Vacuum leak would make it add fuel. Maf should impact both banks. M52tu 2.8 Active Autowerke tune, m54 3.0 intake manifold, cat cams. I also have a lumpy idle sometimes with inpa showing misfire at idle sometimes on 5 and 6. Swapped coils and new plugs. No change. Goes well. Am at 5500 feet but am achieving 0 to 60 times of around 6.5 seconds which is about what I would expect at sea level. We are down 17% on power at this altitude.

I think it's hardware but where to look? Am out of my depth.

Cheers

 

[NZ00Z3]

Code 228 (Dec), P1198, Mixture Deviation Bank 2

It's saying that you have a mixture problem on bank 2 and the DME is having a hard time compensating/controlling it. It could be a rich or lean condition.

Have a look at your 4 fuel trims, both short and long term on both banks. If any are > +/- 8%, then you have a problem to find.

If it's rich (negative fuel trims) on bank 2 only, look for a leaking fuel injector.

If it's lean (positive fuel trims) on bank 2 only, look for.

• A vacuum leak only associated with bank 2. A rolled inlet manifold gasket of one that has tried to drop out of its grove, when fitting the inlet manifold is a common problem. Smoke test the inlet manifold and get a borescope or mirror so you can see right under the manifold and look for smoke.
• An exhaust leak before the Bank 2 pre-cat O2 sensor. Yes, a leak here will cause lean conditions that an inlet manifold smoke test will not find.
• Quick test for inlet manifold vacuum leaks. Hot engine at idle. Note the 4 fuel trims. If any are > 8% then you likely have a vacuum leak. Rise rev's to 3,000 rpm for 30 seconds while watching the fuel trims. If the short term fuel trims drop significantly, might even go negative, then it's confirmed that you have vacuum leaks to find.

 

[Sajk]

Its rich. -16% bank 2. I have an idle misfire bank 2 number 6. Upgraded injectors a while ago for bigger cams. Will start there. Might also replace bank 2 o2 sensor first as that's easier