I have a 89 TPI 5.0 7ooR4. I have gone through 5 mass air flow meters.two used units and three remanufactured units. the code still comes on. the last unit i purchased was suppose to be new from a company named delphi that supposedly took over for GM parts. his new unit is still making the code 33 to go off. I tried to replace both of those sensors on the firewall. that did't work. It is a newer harness and pigtail plug. I tried to wiggle the plug when the car was running to see if the code would go off, but no luck. the code goes on about 5 seconds after the car is started. the computer is a newer remanufactures unit also. what now? i am running out of money over this code. the car seems to run ok even with it on. but it drives me crazy since i only have 62,00 orig miles on the car. please help because i am running out of money

 

I'm assuming you mean manifold absolute pressure (MAP) sensor? The TPI engines did not have a mass air flow (MAF) sensor. Code 33 is for "MAP SENSOR HIGH".

I would check for intake leaks or other causes of improper manifold vacuum at this point. It would be helpful to know what your manifold vacuum reading at idle is.

 

[QUOTE=vgeglia;4421968]I'm assuming you mean manifold absolute pressure (MAP) sensor? The TPI engines did not have a mass air flow (MAF) sensor. Code 33 is for "MAP SENSOR HIGH".
QUOTE]


yes they did i had a 89 iroc 350 tpi and it had a bosch mass air flow