Fault codes vs executive v6

[jeepster]

So if there was a misfire could it come up these codes or visa versa

No misfire codes with VS, but it does have a few "rich/lean/fuel delta trim" that come up with a bad exhaust sensor. I would guess with those 5 codes that the PCM has gone out of closed-loop mode and is not reporting any others.

 

[maddhatter44]

No misfire codes with VS, but it does have a few "rich/lean/fuel delta trim" that come up with a bad exhaust sensor. I would guess with those 5 codes that the PCM has gone out of closed-loop mode and is not reporting any others.

No misfire codes with VS, but it does have a few "rich/lean/fuel delta trim" that come up with a bad exhaust sensor. I would guess with those 5 codes that the PCM has gone out of closed-loop mode and is not reporting any others.

No misfire codes with VS, but it does have a few "rich/lean/fuel delta trim" that come up with a bad exhaust sensor. I would guess with those 5 codes that the PCM has gone out of closed-loop mode and is not reporting any others.

So in a way that I can comprehend how do I fix this or what are my next things to look at?

 

[Grimes]

Replace the oxy sensors first. When reading and addressing codes fix the first one first, then reset the ECU codes with a battery disconnection, drive it around and check them again to see what, if any are remaining. Sometimes a fault on one sensor can induce more signals to log a code which is what jeepster is saying. This is because the ECU is trying to compensate for the dud sensor(s) to keep the engine operating.

I’d replace both, but if you’re hard up for the cash, start with the RH one.

 

[jeepster]

The error codes relate to 4 different sensors. The easiest one to get at is Mass Air Flow Sensor behind the air filter. You can unclip the plug underneath. I put a voltmeter on the 2 outside pins and get 6.5 volts (ignition on, but engine not started). Between the middle pin and one of the others (forgot which) there was 11.5 volts. The engine coolant sensor is under the ignition coils and behind the serpentine drive belt. If you get the plug off, there is supposed to be 5 volts on that. But you would have to poke 2 wires into the plug to measure voltage. It is rather awkward if you aren't used to working on engines. The coolant temperature sensor can be found for about $25 and cheap Chinese Mass Airflow Sensors for $40, but changing them probably won't help. It does sound like the problem is elsewhere.

 

[maddhatter44]

So after a compression test al cylinders around 130 psi give or take 5/10 but cylinder 3 is 75psi

 

[ephect]

Do a wet compression test on cylinder 3 to see if it comes up in psi

 

[maddhatter44]

Do a wet compression test on cylinder 3 to see if it comes up in psi

90 it’s weird I finally reset the ecu and now there’s no codes but it’s clearly not running right

 

[losh1971]

Might be time for a new engine. While 135psi is still OK it's not where a good engine would be at around 180. Plus 90 in one cylinder is not good, it wont run right like that.