Talk Morgan Forums Morgan Sports Cars Morgan Three Wheeler & Super 3 CEL P0173 - Rear Adaptive Maxed Out - Help

So I have been living with CEL P0173 since purchasing my M3W about a year ago.

When I got the car it had a Kuryakyn air cleaner that did not have the necessary little 'ears' that attach to the cylinder heads for support. So I removed the Kuryakyn and installed a S&S Stealth air cleaner that has the proper supports.

The car ran reasonably well with either air cleaner and with the S&S air cleaner P0173 even disappeared for a number of months, only to reappear, then disappear, etc. As others have said here one of the major culprits of P0173 are air leaks at the intake gaskets. I figured that Kuryakyn air cleaner had beat up the rear cylinder intake gasket.

So this last week I replaced the intake gaskets. The rear cylinder gasket did look a bit different than the front cylinder so I thought I had found the problem.

Upon test-starting the car after the new gaskets the CEL went away within about 4 restarts. Car ran a bit rough but nice and smooth in gear.

Unfortunately now with maybe 10 miles on the car the CEL is back on..... with my old friend P0173.

So what is my next move?

1) Swap the exhaust sensors side to side to see if the CEL follows the (bad) sensor? Clean the exhaust sensor electrical connections? Replace the rear cylinder sensor?
2) Unwrap the header pipes and check for cracks in the exhaust manifold?
3) Replace the exhaust manifold gaskets?
4) Or ?


Any input would be great. It was a good feeling to have the CEL go out after the new gaskets and I would sure like to find what is causing that code and get the car running in top shape again.

If it matters - the car has a Garage 56 Stage 1 Exhaust in addition to the S&S Stealth air cleaner.

The simple thing would be to swap the lambda sensors around. You can also use carburetor cleaner or brake cleaner to tray to find the leak if there is one. If you're not familiar with how to do this. Start the engine. Let it idle. Spray the cleaner around where you suspect a leak. The rpm will increase if the intake is able to suck in the cleaner. You could also try a gasket maker or adhesive to help ensure a tight seal. If your adaptive map is maxed out you might want to consider clearing the adaptive map. Perhaps it is showing the code in error due to the maxed out maps. Just my thoughts.

The intake pipe was wrong on mine after thé kuryakin was installed without cylinders supports.
Gaskets were not enough i changed intake pipe

Swapped Lambda sensors side to side - no difference. Tried starter fluid on the rear cylinder at the intake gasket in several different locations - no change in RPM. Just disconnected the battery overnight to clear the adaptive map - assuming that is how it is done.

Atlanda83 - can you elaborate on how your intake pipe was wrong after a Kuryakyn air cleaner was used on your car? Was it bent? If so were you able to detect the leak at the manifold with starter fluid, etc? How did you determine the intake pipe was wrong?

Car is running rough now.

Make sure your injector wires are not miss-matched. The driver’s side (LHD) is marked with masking tape.

The factory had done it
It was blowing

Just checked the injector wires - driver's side has the masking tape. Whew. I should add I just installed new injectors less than 500 miles ago.... so mismatching the wires was a possibility I had not thought of kankeL. Thanks!

Thank you Atalante83 for clarifying. I do not think my intake is deformed because I cannot get the air leak to show itself with starter fluid, fogging oil, etc. Plus the CEL went away immediately after I installed new intake seals. Only to return just 10 miles later.

Did you check your fuel pressure? Did you clear codes/re-set adaptive maps in S&S ProTunes? Try to feel for exhaust leaks around the exhaust flange?

Aslo, probably makes sense to clean the MAF sensor with some throttle body cleaner?

Also, my air temp sensor (a tiny one), was pretty loose and was showing signs of oil leaking though the gasket. Check that also.

Fuel pressure was checked and is where it should be - the pump and filter are new within last 500 miles. Checked for exhaust leaks but will check again. I did clean the air temp sensor - that one was pretty dirty!

My MAP (Manifold Absolute Pressure) Sensor, the flat one that plugs into the manifold itself, was also really dirty and the gasket showed signs of oil leaking past it. The MAP sensor almost looks like a universal part used across a wide variety of vehicles, including lots of GM products. Strangely the MAP Sensor is not listed on the M3W Alternative Parts List. Anyone know the alternate part number for this one? The S&S Part number is 55-1037.

Just read the ProTune manual on how to reset the adaptive maps so I will do that tomorrow.

I have not heard of any problems with the MAP sensor before, so no one has supplied the information about what an alternative may be yet. The list is only as good as the information that is shared here. If you find that information please let me know and I will add it to the Alternative Parts List. The sensors all seem to be HD items and these are usually easier to find alternatives for.

If you are running the original specification fuel pump I would advise replacing that. Maxed out adaptive maps seems to be a common first sign of pump failure and the original pump will fail at some point anyway. Just had a look at your April posts and you seem to have changed the pump already, although not sure what you have now as it was changed about a few times with fuel pressure issues still, did you resolve them in the end? As mentioned, the maxed out adaptive maps is usually the ECU trying to compensate for low fuel supply pressure.