Jerky cruising speed and running lean
07-13-2022, 10:37 PM
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Jerky cruising speed and running lean Hi all,
I have been searching the threads the past few weeks in search of a solution and have tried a few things without much luck. Looking for some guidance.
2001 WS6 with 50,000 miles on it. K&N FIPK filter, long tube headers, off road y pipe, and flowmaster muffler. Beginning of this year, I noticed some new codes being thrown. P0102, P0135, P0155, P0801. After realizing all of these codes correspond to the ENG SEN fuse, I decided to check it and sure enough, the fuse was blown. Replacing it resulted in the same thing, blown within 50 miles of driving, but not immediately.
I decided to clean the MAF without any luck. I replaced it with an aftermarket, blue streak electronics, MAF and things changed. The car now does not throw any of those original codes, however, it now violently jerks while cruising. The rear 02 codes are being thrown, I have simulators on that must not be working anymore. I will eventually have these tuned out. Although, bank 2 was now running lean, P1153.
I had some diagnostics done by a tuner and he said the O2 activity on bank 2 was dead. Recommended new sensors and spark plugs. I bought AC Delco replacements and had them installed this week. The car still violently shakes and is now also running lean on bank 1, P1133, and bank 2.
My thought is maybe the aftermarket MAF is not cooperating? My car only starting driving poorly after it was installed. Is it worth buying an AC Delco MAF and trying?
Other solutions I have read that seemed to fix the bucking/jerking driving is changing fuel filter/pumps and checking vacuum leaks. Other than installing a new MAF, I would have to use a shop for this other work and the costs are starting to add up.
I do own a Diablosport tuner that I use to read codes and pull some data. Way back in the day I had a fellow ls1tech member MonteSS give me a tune after my header install and I remember him commenting on the values I sent him and how they were a bit unusual ( I dont remember specifics). Until recently, I haven't noticed a drop in performance of the car.
Any help would be apprecaited.
I have been searching the threads the past few weeks in search of a solution and have tried a few things without much luck. Looking for some guidance.
2001 WS6 with 50,000 miles on it. K&N FIPK filter, long tube headers, off road y pipe, and flowmaster muffler. Beginning of this year, I noticed some new codes being thrown. P0102, P0135, P0155, P0801. After realizing all of these codes correspond to the ENG SEN fuse, I decided to check it and sure enough, the fuse was blown. Replacing it resulted in the same thing, blown within 50 miles of driving, but not immediately.
I decided to clean the MAF without any luck. I replaced it with an aftermarket, blue streak electronics, MAF and things changed. The car now does not throw any of those original codes, however, it now violently jerks while cruising. The rear 02 codes are being thrown, I have simulators on that must not be working anymore. I will eventually have these tuned out. Although, bank 2 was now running lean, P1153.
I had some diagnostics done by a tuner and he said the O2 activity on bank 2 was dead. Recommended new sensors and spark plugs. I bought AC Delco replacements and had them installed this week. The car still violently shakes and is now also running lean on bank 1, P1133, and bank 2.
My thought is maybe the aftermarket MAF is not cooperating? My car only starting driving poorly after it was installed. Is it worth buying an AC Delco MAF and trying?
Other solutions I have read that seemed to fix the bucking/jerking driving is changing fuel filter/pumps and checking vacuum leaks. Other than installing a new MAF, I would have to use a shop for this other work and the costs are starting to add up.
I do own a Diablosport tuner that I use to read codes and pull some data. Way back in the day I had a fellow ls1tech member MonteSS give me a tune after my header install and I remember him commenting on the values I sent him and how they were a bit unusual ( I dont remember specifics). Until recently, I haven't noticed a drop in performance of the car.
Any help would be apprecaited.
07-14-2022, 06:50 AM
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07-14-2022, 08:30 PM
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I have an 85mm ZO6 MAF. I was having some issues and I thought it might be a MAF problem. Got a truck MAF off ebay and it had a different resistor and ran like crap. Put the old MAF back on and it ran fine. I found my problem to be a bad new O2 sensor.
07-15-2022, 06:01 PM
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Now Bank 2 is running lean, not bank 1 anymore. The car is driving smooth so far.
Could I just need a tune to improve bank 2 fuel trims or is there an underlying problem there?
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07-16-2022, 08:48 AM
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Started running lean on bank 1 this morning. Now both banks are back to running lean. The jerky driving has completely stopped though which is what bothered me the most.
LTFT values seem to stay within 5% so I'm not sure why the codes are even being thrown. What is the range the car will tolerate before being considered too rich or too lean?
LTFT values seem to stay within 5% so I'm not sure why the codes are even being thrown. What is the range the car will tolerate before being considered too rich or too lean?
07-16-2022, 08:50 AM
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07-16-2022, 08:57 AM
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Has the car been tuned since the headers were installed?
If no exhaust leaks or vacuume leaks are found I would check the plugs to see if it’s lean or not, if not I would just disable those codes since you have longtubes.
Would be best to check it with a wideband.
But that’s just me…
If no exhaust leaks or vacuume leaks are found I would check the plugs to see if it’s lean or not, if not I would just disable those codes since you have longtubes.
Would be best to check it with a wideband.
But that’s just me…
07-16-2022, 09:01 AM
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Has the car been tuned since the headers were installed?
If no exhaust leaks or vacuume leaks are found I would check the plugs to see if it’s lean or not, if not I would just disable those codes since you have longtubes.
Would be best to check it with a wideband.
But that’s just me…
If no exhaust leaks or vacuume leaks are found I would check the plugs to see if it’s lean or not, if not I would just disable those codes since you have longtubes.
Would be best to check it with a wideband.
But that’s just me…
07-16-2022, 11:13 AM
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I do have exhaust leaks at the y pipe but the leaks are after the upstream 02 sensors. So while this may be a concern, it should not be the reason I’m running lean, correct?
Trying a vacuum test next
Trying a vacuum test next
07-16-2022, 01:12 PM
#14
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How far from the O2 sensors?
It can affect it....
It can affect it....
07-16-2022, 01:32 PM
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07-16-2022, 01:57 PM
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The first leak WILL affect O2 readings. Try to fix it.
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07-16-2022, 05:30 PM
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Working on the exhaust leaks. I hooked up the car to a vacuum tester and was getting low and steady readings, about 12 inHg. I'm most likely taking it back to the shop to have both the vacuum leak fixed, wherever it is, and the exhaust leaks sealed.
