P2a00

2010 Honda Element LX 2.4
P2A00 returned after replacing af sensor. All wiring, connections, fuses, and relays have been checked several times. New plugs, air filter, and PCv valve. Runs fine. No other codes. When monitors complete, it throws code. It is barely out of range on Comp. ID $84. Good compression. No intake or exhaust leaks. This is keeping an elderly customer from NH state inspection. Any idea what I am missing? Is there a recalibration to widen parameters that I am not aware of ? Any input or advice will be greatly appreciated.

What brand of replacement A/F sensor did you use? It's been my experience that Honda/Acura products don't play nice with anything other than OE. You can get away with aftermarket parts on other makes, but not this one.

For what it's worth, this is the Honda flow chart for P2A00. It's (surprisingly?) straightforward:



tl;dr - Warm up the car, drive it for five minutes, do a closed throttle decel. Did the code set? Replace the sensor. :silly:

Tyler wrote: It's (surprisingly?) straightforward

There is one "Gotcha" in there. Step 9 calls for resetting the ECM with HDS after replacing the A/F sensor. Guessing it learns the A/F sensor and a reset is required to force a learn on the new one.

The sensor is a genuine Denso purchased at local Honda dealer. Watching live data,ot appears to be functioning properly on heater and air/fuel sides. But when readiness monitor completes, it is just slightly out of parameters on 1 test. I will look into a relearn procedure. Thanks for the tip. I have Identifix and Shopkey Pro, and they both give the same information that you posted. I will update whenever there new development.

After a MAF swap (had a good used 1in shop) the MA on af rationality get a little closer to acceptable parameters. Before the test value was -2.590mA. With MAF swap the test value is now -2.492mA. The desired range is MIN-2.324mA
MAX-.0445mA
I have another new sensor (OEM Denso from stealership) coming on delivery truck now. Will update with results. The difference of 0.148mA will hopefully be corrected with another sensor. If not it's back to square 1.

After running all possible tests, and replacement of parts, I am now thinking that the ecm needs to be replaced, or flashed. Will check to see if there are any updated calibrations for this and update as soon as anything changes.