Dreaded p0068

[RLnewbie]

Car is a 05 ion redline with short ram intake, catless, eaton with 2.8 pulley and 60 lbers. This is the same setup for the last 60k currently has 129k. Yes i did search and tried some of the solutions. Any other ideas would be great.


On my way to work the other day and the car hesitated pretty badly. Kept on going and it got worse all the way to a full blown misfire. Shut the car down. Had to have the wife bring the laptop. Codes were
p0121 Throttle Position (TP) Sensor Performance
p1101 Intake Air Flow System Performance
p1182 Supercharger Inlet Pressure Sensor Performance
p1183 Supercharger Inlet Pressure Sensor Circuit Low Voltage
p0068 Throttle Body Airflow Performance
p2228 Barometric Pressure (BARO) Sensor Circuit Low Voltage

Took it home. Checked plugs. Looked questionable and was something i needed to do anyway. Replaced and test drove. Still started misfiring. Removed intake. Cleaned Maf and throttle body. Inspected supercharger inlet pressure for carbon or debris build up. Test drove and misfired followed by limp mode. Decided to replace Maf. Maf had build up and dirt on it so i decided to replace it. After driving it took a while for it to come back on but i got a
p0101 MAF sensor performance
p0068 Throttle body airflow performance.


I have searched a number of places. Most say to disable these codes,but i don't see why the same tune for 60k would cause something like this now?
Any thoughts would be helpfull.

I'm going to try and include the log from hpt. Misfiring starts close to frame 1100. When in limp mode it looks like the ETC sets a 30% and stays there.

[Hypertension]

bump to get some intelligent discussion going, GL

[recaro86]

Just curious how dirty is the air filter, and what does the plug gap look like? I'm not sure what you have tried so far, but this is where I would start.

[RLnewbie]

All gaps were checked when installed at 35. Air filter was replaced about 3 months ago. Still looks fairly clean. I disabled p0068 and p0101 in HPT engine diagnostics based on some advice i was reading on Hp Tuners. By disabling i mean setting the engine temps and rpm settings higher than attainable so i could let the computer fail enough that i might see the sensor spike on a graph. Went out for a drive and i got
P0171 Fuel Trim System Lean ECM
P0172 Fuel Trim System Rich ECM

The car didn't go into limp mode or misfire after failing those 2 codes.
Intake manifold vacuum was at 10-12 in with cruising at 60 mph which seemed a little high to me. When i got back i let the engine sit at idle and sprayed starting fluid around some of the intake hoses to try to get a change in rpm. Nothing so far has led me in a specific direction. I might have to start digging on the wiring or have an intermitant shorted sensor. I do notice my SAE baro sometimes goes to zero and Ambient air temp SAE drops out to -40. That is the only ones that change,but the secondary readings i have that are attached to those sensors don't change.

[RLnewbie]

Here is the Hp Tuners Log for cruising when the 0068 was disabled. Thanks for the ideas BTW.

[recaro86]

Sorry we couldn't help, the problem will no doubt rear its ugly head soon enough. Sounds like it has been fixed for the time being.

[slitterell]

I had something similar. I replaced tb and it cleared up.

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