Mechanics

RUNNING ON 4 CYL. ?????

1997 Cadillac Seville

Engine Performance problem
1997 Cadillac Seville V8 Two Wheel Drive Automatic 103000 miles

I just changed the head gasket on this Northstar engine( new certs and all) everything went fine but the car is now running in limp home mode (4cyl) I tried clearing the codes twice but still running on 4 cyl I need help. Thanks in advance
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Rich2379
October 24, 2009.



In clearing the codes twice, what codes are they? If they keep resetting, it can be that a hard fault exists that is the root cause.

Factoryjack
Oct 26, 2009.
The codes that keep returning are ones that refer to the o2 sensors (exhaust) thats it. Has me stumped. Any help

Tiny
Rich2379
Nov 9, 2009.
In my information, I do not find any info on limp home, and what it does. What is missing from the cylinders that are not firing, injector pulse or spark? There are two injector power fuses that serve four cylinders each. One fuse powers 1, 4, 6, and 7, the other 2, 3, 5, and 8. These are in the underhood fuse block. The PCM has individual drivers that control the ground of each individual injector. I think that in the event of an overheat, cylinders will drop off to try and bring the temp down. If you are just getting O2 codes, that should not cause cylinders to disable. Check that both these fuses have power to, and across them, and/or check that each injector has power to it on the pink wires.

Factoryjack
Nov 9, 2009.
Thanks for the info I will check out the fuses and let you know again thanks for the help

Tiny
Rich2379
Nov 9, 2009.