Rich air fuel mix problem

[dtennes]

Heads up. I have a problem with "rich" fuel trims, both short and long.

Background: I had elected to replace all of the emission-related sensors (MAP, ECT, IAT, etc) and fuel-air mix controllers (Intake Air Control Valve, Throttle Position sensor, Evap purge) that I could do myself.

In the precess of replacement I found a broken o-ring on the MAP sensor, which might explain the PCM pumping extra fuel and causing the "rich" mix.

I bought a new MAP sensor from AMZN and put it in, o-ring properly seated. Still suffering a "rich" mix condition. LTFT1 > 14.0 LTFT2 > 20.0.

Went back and reviewed parts ordered from AMZN, and thanks to their incorrect "fitment" feature, I found out that I bought the wrong MAP.

I am now waiting for the arrival of the correct part and will update this after installation and testing.

AMZN fitment disinformation: 56041018AB
Correct MOPAR part: 68002763AA

Look here (or similar elsewhere) for the correct MAP fitment: https://www.quadratec.com/products/55122_2005.htm


My own fault for trusting AMZN and their sponsored Chinese Supply Chain

 

[Xterra4x4]

Heads up. I have a problem with "rich" fuel trims, both short and long.

Background: I had elected to replace all of the emission-related sensors (MAP, ECT, IAT, etc) and fuel-air mix controllers (Intake Air Control Valve, Throttle Position sensor, Evap purge) that I could do myself.

In the precess of replacement I found a broken o-ring on the MAP sensor, which might explain the PCM pumping extra fuel and causing the "rich" mix.

I bought a new MAP sensor from AMZN and put it in, o-ring properly seated. Still suffering a "rich" mix condition. LTFT1 > 14.0 LTFT2 > 20.0.

Went back and reviewed parts ordered from AMZN, and thanks to their incorrect "fitment" feature, I found out that I bought the wrong MAP.

I am now waiting for the arrival of the correct part and will update this after installation and testing.

AMZN fitment disinformation: 56041018AB
Correct MOPAR part: 68002763AA

Look here (or similar elsewhere) for the correct MAP fitment: https://www.quadratec.com/products/55122_2005.htm


My own fault for trusting AMZN and their sponsored Chinese Supply Chain

I to bought a MAP sensor from Amazon, I always check package to see if part is old or new? I have problems with Amazon, I buy a lot of part from rockauto!

 

[dtennes]

Installed the "correct" MAP #68002763AA, and it seems to have partially improved the fuel trim. I had unstable o2 sensor readings prior to MAP replacement were sticking between .07 and .65 V, with 1 sensor occasionally hitting .8... and my understanding is that its supposed to fluxuate between .1 and .9

Now 3 out of 4 o2 sensors are fluxuating between .1 and .85.

I think I may have a bad downstream o2 sensor and will be replacing that soon.

 

[Xterra4x4]

Heads up. I have a problem with "rich" fuel trims, both short and long.

Background: I had elected to replace all of the emission-related sensors (MAP, ECT, IAT, etc) and fuel-air mix controllers (Intake Air Control Valve, Throttle Position sensor, Evap purge) that I could do myself.

In the precess of replacement I found a broken o-ring on the MAP sensor, which might explain the PCM pumping extra fuel and causing the "rich" mix.

I bought a new MAP sensor from AMZN and put it in, o-ring properly seated. Still suffering a "rich" mix condition. LTFT1 > 14.0 LTFT2 > 20.0.

Went back and reviewed parts ordered from AMZN, and thanks to their incorrect "fitment" feature, I found out that I bought the wrong MAP.

I am now waiting for the arrival of the correct part and will update this after installation and testing.

AMZN fitment disinformation: 56041018AB
Correct MOPAR part: 68002763AA

Look here (or similar elsewhere) for the correct MAP fitment: https://www.quadratec.com/products/55122_2005.htm


My own fault for trusting AMZN and their sponsored Chinese Supply Chain

A thought! The cruise control is vacuum and line is connected under the coolant resivor with vacuum line controlling the a/c and heat positions, the line connects to the back of the intake manifold (maybe crack in line some where (check)

 

[Ksat]

The downstreams usually don't have any effect on the air/fuel mix.

What do the short and long terms look like now at idle?

 

[dtennes]

A thought! The cruise control is vacuum and line is connected under the coolant resivor with vacuum line controlling the a/c and heat positions, the line connects to the back of the intake manifold (maybe crack in line some where (check)

A very interesting thought, because I have what looks like a "rogue vacuum line" that has an end with some sort of weird white-plastic-breather plug stuck in it. The garage said it was "a transmission breather line" but I've been to the salvage yard a few times looking at 2003 3.7L intact drive trains, and I cannot find any similarity between this "dangler" and what's sitting intact in the yards.

I will take a pic and attach this morning.