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- - OBD code 21 & 87 (https://67-72chevytrucks.com/vboard/showthread.php?t=770732)

lofly'a

09-04-2018 11:13 AM

OBD code 21 & 87

My 94 Cheyenne 350/4L60E has 2 codes, 21-TPS signal high, and 87-EEPROM flash memory error. On 21, I changed the TPS (housing was cracked) before it had this problem, and all was well for a short time then truck started stumbling off-idle and idling high. Also What are effects of 87? No vacuum leaks, no miss, just hesitation & high idle. I notice a difference in shift points also. Anybody?

mikebte

09-11-2018 03:23 PM

Re: OBD code 21 & 87

1 Attachment(s)

Still having the issue?
Have you tried hooking up a vacuum gauge and seeing whats it says?

Saw this on another post, may help you get started. Hesitation can be a few things but good to start with a vacuum gauge.

AussieinNC

09-16-2018 01:58 PM

Re: OBD code 21 & 87

Check the 10 amp fuse in the fuse panel labelled Trans...87 code can be set if this fuse blows...:chevy::chevy::chevy:

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