97 GTS - INTERMITENT ENGINE MISS

[gary linafelter]

CHECK ENGINE LIGHT CAME ON. HAD CODE P1398. I CHANGED SPARK PLUGS, WIRES,AND COILS. I RAN SEVERAL BOTTLES OF TECHRON THROUGH THE TANK. A MECHANIC DROPPED THE CODE AND HAD THE PCM RE-LEARN TIMING. 1000 MILES LATER, CHECK ENGINE LIGHT IS BACK ON AND I ALWAYS HAVE HAD AN INTERMITENT MISS. THE MISS IS OFF IDLE TO ABOUT 2800 RPM. ANYBODY HAD THIS PROBLEM,OR KNOW WHAT'S GOING ON?
THANKS, GARY

 

[GTS Dean]

Maybe a long shot, but 2800 is about where the motor goes into open loop, runs off the base map and pulls data from fewer sensors. Perhaps something as simple as an O2 sensor?

 

[1MEANSNAKE]

I believe it is the 02 sensor, mine just went out as well and is about to be replaced. Contact Chuck Tator

 

[gary linafelter]

CHUCK TATOR AND GTS DEAN- THANKS! I'LL CHECK IT OUT, AND POST A REPLY WHEN I GET IT SOLVED.
GARY L

 

[Joseph Dell]

O2 sensor is an easy part to replace too. autozone or pep-boys should stock them. go get a pair and see if that fixes it.

Oh yeah.... we are talkin' fronts and not rears...

Good luck!

JD

 

[Sean Roe]

1398 is a camshaft / crankshaft sensor code.