wheelin today and a couple of issues

[f5fstop]

Dealer can reset codes with a Tech 2. If he is trying to duplicate the problem, he might have to go on a high-altitude trip.

Didn't see the codes earlier.

P0068 Poor flow (with this code, the airflow is actually larger than expected)
P0171 Lean Code Bank 1 (Do you have an aftermarket air filter?)
P0121 Throttle Position Sensor Performance (TP sensor 1, and is related to a larger than expected intake of air)
P0016 Map Sensor (This code is set due to a camshaft position sensor pulse occurs during the incorrect crank position).
Either 68 or 121 can cause the PCM to go into reduced power mode. I'm guessing, and that is all it is, the PCM got a bit mixed up for some reason. One of the sensors that the PCM uses to monitor airflow (TP/BARO/MAP/IAT/MAF/RPM) could be failing, but not sure which one; it should set a code.

However, I do not see how a cat-back exhaust would cause any of these problems. If you had installed headers...maybe. But a new lower restricted exhaust and new pipes after the muffler should not cause any of these problems. I would ask the dealer to substantiate why he even thinks the exhaust will cause this problem.


How is your idle now that you have returned to the 6K range? That P0016 is out of place. If you had that one, and some P0300+ codes, along with a rough idle, I might suggest a cylinder head issue. But the cylinder head issue does not shut down the vehicle, it only causes a rough idle and sets codes.

I can find nothing in preliminary reports or in bulletins; other than for 171 where it states the air filter can be restricted, or PCV hoses kinked.

I will print this off tomorrow at work, and if the programming dude is around I will show them to him and see what he thinks.
I know he is hot and heavy on a new chassis cal that has to be released, but it outputs chassis codes when the condition happens, and so far, only a half-dozen complaints from customers, but quite a few from some engineers running the trails somewhere in the US.

DTC P0016
Circuit Description
The powertrain control module (PCM) uses the crankshaft position (CKP) sensor and the intake camshaft position (CMP) sensor information to monitor the correlation between the crankshaft and intake camshaft position. If the PCM detects a CMP sensor pulse occurs during the incorrect crank position DTC P0016 will set.

DTC P0068
Circuit Description
The powertrain control module (PCM) uses the following information to calculate an expected airflow rate:

? The throttle position (TP)

? The barometric pressure (BARO)

? The manifold absolute pressure (MAP)

? The intake air temperature (IAT)

? The mass air flow (MAF)

? The engine RPM

If the PCM detects the airflow rate is more than expected, DTC P0068 sets.

DTC P0121
Circuit Description
The powertrain control module (PCM) uses the following information to calculate an expected airflow rate:

? The throttle position

? The barometric pressure (BARO)

? The manifold absolute pressure (MAP)

? The intake air temperature (IAT)

? The mass air flow (MAF)

? The engine speed (RPM)

If the PCM detects the airflow rate is more than expected, DTC P0121 sets.