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Hey guys my check engine light stated flashing this week. I haven’t noticed a difference in performance at all. I pulled the codes today and got code 87 with the key on and engine off. I know that code 87 means fuel pump primary circuit failure. With the key on engine running I got code 91. I know that code 91 means left HEGO system indicates system lean. Could this be caused by a bad O2 sensor on the left side? Would that cause a problem with the fuel pump or could my fuel pump be getting ready to crap out, causing a problem with the left side O2 sensor? The funny thing is that I'm not getting a code 41 for the right side HEGO indicating lean. Any help you guys can give would be much appreciated! Thanks again!
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Switch O2 sensors from sides.... if code 41 shows afterward, that O2 (now on the RH side) needs a replacement.
__________________ ACRONYMS:
LUK=Let Us Know, GL=Good Luck, LMK=Let Me Know, JIC=Just In Case, BTSTDTRT=Been There Seen That Done That Repaired That, YCYDYP=Your Car Your Dough Your Prerogative and the classic... DILLIGAS=Do I Look Like I Give A S***
1986 GT-X303-289 heads-1.72 rockers-RG 4+1 Trans.
Quote:
Originally Posted by Joel5.0
Great thoughts will overwhelm a feeble mind.
There is never money to do it right, but there's always money to do it over.
The proof of understanding is the ability to explain it. (H. Torruella)
Different issue.... as soon as you ID if the O2 needs to be replaced..... clear codes and then retest for code 87, which means there could be a problem in the FP relay coil circuit.
__________________ ACRONYMS:
LUK=Let Us Know, GL=Good Luck, LMK=Let Me Know, JIC=Just In Case, BTSTDTRT=Been There Seen That Done That Repaired That, YCYDYP=Your Car Your Dough Your Prerogative and the classic... DILLIGAS=Do I Look Like I Give A S***
1986 GT-X303-289 heads-1.72 rockers-RG 4+1 Trans.
Quote:
Originally Posted by Joel5.0
Great thoughts will overwhelm a feeble mind.
There is never money to do it right, but there's always money to do it over.
The proof of understanding is the ability to explain it. (H. Torruella)
Thanks Joel the problem seems to be fixed! I had an extra O2 sensor lying around, pulled out the old one and put the new one in and cleared the codes. I drove the car around all day and the check engine light didn’t flash one time. When I got home I checked to see if any codes had been stored. To my amazement no codes, not even code 87. Weird but it even idles better...lol. Thanks again for the help!
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Need some help with codes 87 and 91
Thanks again!
