My friend has a 1999 2500 4X4 6.0L. We just put a cold air intake, mass airflow, HPPIII - just for shift points, and two Hooker mufflers dumped, on his truck two weeks ago. Now he has:

P0161 - 02S Heater Circuit Bank2 Sensor2 Malfunction
P0172 - Fuel Trim Bank1 System too Rich
P0175 - Fuel Trim Bank2 System too Rich
P0719 - Torque Converter Switch B Circuit Low

I thought that the mass air leaned out the truck, not richened it up?

Any suggestions?

We did have the 87 tuning in, but he was getting 5 to 9 degrees of knock at WOT. So we took out the tuning.

 

Check the connection on the mass airflow and check for air leaks between the sensor and the throttlebody.If that does'nt work put the stock mass airfiow sensor back on the truck.

 

I'm no expert but it sounds as if its some thing that was done when changing the MAF. Disconnect the battery maybe and chek your MAF connections, (electrical and seals) out and reset the battery? I have gotten some messages and that almost always cleared that way, if all was set right.
Just a guess. Good luck.

 

Thanks, will try that!

 

What kind of maf, GMS? The HPP tuning advances the engine timing as does the GMS maf. The combination of the two is probably to much timing and may be the cause of the pinging. When I had my GMS maf, the truck ran better and was quicker with no HPP tuning and just using the GMS maf along with the raised HPP shift points.
Jim

 

Yes, it is the GMS and there is no tuning, just shift points.