Surging at low rpm, light throttle
08-11-2012, 01:35 PM
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Surging at low rpm, light throttle Bought the car (99SS auto) with lt's, cats, catback, lid, and slp MAS. I noticed a little surging at light throttle low rpm driving, like just cruising along maintaining speed. Right after getting it, took around 300 lbs off it, including all the emission crap, and the surging seemed worse. Recently added a wet kit and had cats removed and the surging is very noticeable. Same rpm and speed as before. If I give it gas it barks a bit and clears up and accelerates fine. Runs great at the track, just notice it at cruising speeds. With the n20 I put in new plugs and wires, and have tried driving it with mas unplugged. No different. Idles fine and doesn't stall. I have a wideband and notice that as I'm cruising steady throttle the a/f climbs starts to get stumbly at 19.1 and very surgy as it pegs the meter at 21.9. If I gently give it a little more throttle it stumbles for a few seconds, then jumps to 16-17.1 , exhaust barks a little and runs fine until it leans back out again. Thoughts? vacuum leak? can't seem to find any. Thanks
08-11-2012, 02:21 PM
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I haven't scanned it, I'm sure it will have a million codes with all the emission's removed. I don't know if it was tuned for the mas, it was on when I bought it. Didn't tune out the rear o2 (maybe I can get simulators?) because I have the predator and I can't turn them off with it, however the surging happened with the cats still in.
08-11-2012, 02:59 PM
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I forgot to mention this before, but since the surging has worsened the check engine light flashes sometimes where it was just solid on before. I will scan the codes
08-11-2012, 03:07 PM
#6
Have you already tried spraying the MAFS with mafs cleaner?
You might also consider posting this in the pcm-diagnostics-tuning forums.
https://ls1tech.com/forums/pcm-diagnostics-tuning-7/
You might also consider posting this in the pcm-diagnostics-tuning forums.
https://ls1tech.com/forums/pcm-diagnostics-tuning-7/
08-11-2012, 03:41 PM
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Have you already tried spraying the MAFS with mafs cleaner?
You might also consider posting this in the pcm-diagnostics-tuning forums.
https://ls1tech.com/forums/pcm-diagnostics-tuning-7/
You might also consider posting this in the pcm-diagnostics-tuning forums.
https://ls1tech.com/forums/pcm-diagnostics-tuning-7/
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08-11-2012, 04:03 PM
#8
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codes:
po102- mass or volume air flow circuit low input
po137- 02 circuit low voltage bank 1 sensor 2
po157- 02 circuit low voltage bank 2 sensor 2
po300- random misfire detected
po405- egr recir. sensor a circuit low
rear 02's make sense without cats, egr is gone so that make sense, ran with mas unplugged so I assume that's the first code.
po102- mass or volume air flow circuit low input
po137- 02 circuit low voltage bank 1 sensor 2
po157- 02 circuit low voltage bank 2 sensor 2
po300- random misfire detected
po405- egr recir. sensor a circuit low
rear 02's make sense without cats, egr is gone so that make sense, ran with mas unplugged so I assume that's the first code.
10-23-2012, 02:33 PM
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po137- 02 circuit low voltage bank 1 sensor 2
po157- 02 circuit low voltage bank 2 sensor 2
Both are because of your lack of cats.
po405- egr recir. sensor a circuit low
No egr.
po102- mass or volume air flow circuit low input
po300- random misfire detected
These two are the ones doing the damage. If you are using K&N filter, you can contaminate the MAF sensor with oil. Also, a dirty filter may do the same thing. I'd try cleaning it. Also, you could have a bad connection to the sensor. Rats might have chewed on it. The sensor itself may be bad. Or the computer may be bad. It's rare but it does happen. Don't know your level of skill but I'd first clean it. If that doesn't work, I'd try replacing it. Note, if it doesn't fix it, take it back and get a refund. Without diagnostic equipment you cant test this stuff properly and the only way to test it is to replace it.
Now on to the random misfire. Could be due to the MAF sensor itself. See if you can resolve the problem with the MAF sensor first. If it doesn't fix it, check plugs, plug wires, coils, or injectors. Anything other than that there are lots of other things as well that get deep into it. Let us know what you find.
po157- 02 circuit low voltage bank 2 sensor 2
Both are because of your lack of cats.
po405- egr recir. sensor a circuit low
No egr.
po102- mass or volume air flow circuit low input
po300- random misfire detected
These two are the ones doing the damage. If you are using K&N filter, you can contaminate the MAF sensor with oil. Also, a dirty filter may do the same thing. I'd try cleaning it. Also, you could have a bad connection to the sensor. Rats might have chewed on it. The sensor itself may be bad. Or the computer may be bad. It's rare but it does happen. Don't know your level of skill but I'd first clean it. If that doesn't work, I'd try replacing it. Note, if it doesn't fix it, take it back and get a refund. Without diagnostic equipment you cant test this stuff properly and the only way to test it is to replace it.
Now on to the random misfire. Could be due to the MAF sensor itself. See if you can resolve the problem with the MAF sensor first. If it doesn't fix it, check plugs, plug wires, coils, or injectors. Anything other than that there are lots of other things as well that get deep into it. Let us know what you find.
01-04-2014, 10:24 PM
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now I have the same problem with my2000 camaro z28 outo. I get a surge when it changes gear and I have the codea coming up as po137 and po157. I have already dont the tranissio. flush and a new trans filter I just dont want it to be my trans.help plz
