How does a car go into reduced engine power when you have no trouble codes, no misfire, no knock? Everything looks great, but the car stumbles and goes into reduced engine power without a single ses code or any misfires or knock.

 

Does it have a full tank of gas? I have read a few posts that have said timing will be pulled if you are low on gas.

 

Does your data stream from the PCM confirm this?
Is it pulling timing?
Running fat?

 

Are you talking limp mode?

 

NO timing is being pulled and it's not running fat. Everything seems fine.

 

This is in a C5, it says reduced engine power on display. All readings from tech 2 seem perfect, and bam, just dies. Well it misses t hen dies, but funny thing is no engine misfires detected.

 

Check for non powertrain codes through the DIC (Hold options and press fuel four times). You could have a brake, steering or active handling problem.

 

When is this happening?
I have had a lot of reduced power(limp mode)over the years.
If you have the 1514 code shut off,it still will go into reduced power, but doesn't set the code.
It seems that when the MAF and TB get out of sync just a little the engine shuts down(reduced power).
Tom Hall
97 C5
422

 

Try removing the neg lead on the battery for a minute and see if it resets then recheck for codes. I have seen this happen on a truck before.

 

Horist had this problem, where is he.

 

mine was a differnt problem Mine was due to the knock sensor wire grounding out so setting knock sensor code was being set and sending me to low octane tables. But my issue was setting codes....