New engine questions/issues
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Teching In
Joined: Mar 2007
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New engine questions/issues Over the winter i had my LS1 rebuilt using a Texas speed head/cam combo, new crank and pistons as well as a fast 92 intake and throttle body. Running a painless wiring harness with a GM computer. Also just installed a new T56. All of this was swapped into a 1980 Trans Am. Car was dyno tuned and put 424 to the wheels. During the dyno session they mentioned they were unable to get readings from both of the O2 sensors. Later on inscanned the car and found both sensors were reading. At idle they were around 409 and at 5000 RPMs they were around 440. Is that a normal range or should they he reading higher than that?
Second issue i am having is a check engine light from a PO103 which is a MAF high circuit. I checked the wiring for damage as well as replaced the MAF and the code came right back. The car also seems to randomly stall when coming to a stop or when your cruising and just shift into neatural.
anyone have any solutions or ideas on where to start?
thanks in advance for the help
Second issue i am having is a check engine light from a PO103 which is a MAF high circuit. I checked the wiring for damage as well as replaced the MAF and the code came right back. The car also seems to randomly stall when coming to a stop or when your cruising and just shift into neatural.
anyone have any solutions or ideas on where to start?
thanks in advance for the help
TECH Fanatic
Joined: Oct 2014
Posts: 1,220
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From: Virginia
Over the winter i had my LS1 rebuilt using a Texas speed head/cam combo, new crank and pistons as well as a fast 92 intake and throttle body. Running a painless wiring harness with a GM computer. Also just installed a new T56. All of this was swapped into a 1980 Trans Am. Car was dyno tuned and put 424 to the wheels. During the dyno session they mentioned they were unable to get readings from both of the O2 sensors. Later on inscanned the car and found both sensors were reading. At idle they were around 409 and at 5000 RPMs they were around 440. Is that a normal range or should they he reading higher than that?
Second issue i am having is a check engine light from a PO103 which is a MAF high circuit. I checked the wiring for damage as well as replaced the MAF and the code came right back. The car also seems to randomly stall when coming to a stop or when your cruising and just shift into neatural.
anyone have any solutions or ideas on where to start?
thanks in advance for the help
Second issue i am having is a check engine light from a PO103 which is a MAF high circuit. I checked the wiring for damage as well as replaced the MAF and the code came right back. The car also seems to randomly stall when coming to a stop or when your cruising and just shift into neatural.
anyone have any solutions or ideas on where to start?
thanks in advance for the help
For the codes, unfortunately 99% of the time it’s a physical issue and not a tune. However, without seeing a log or tune file, tough to say really. The O2’s won’t help you for stalling, especially if the engine is flooding or what not because of shoddy readings. I can’t count how many threads are in this forum of similar problems because of bad O2’s. Typically exhaust leaks and super rich readings on one bank, etc, and the occasional flat lined one as you are describing. The shop that tuned it probably should of verified the wiring was right. Got to check the pins, PCM model, year, all of it to be sure. As I have found, P01 PCM’s don’t all have the same pin outs through the years, which is a real pain in the ***. Depends on what it was installed in in the first place.
Teching In
Joined: Aug 2019
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The O2’s should not remain constant. If the reading remains the same, they aren’t reading properly. They should be constantly switching back and forth, ranging from about 200 mv to 800 mv, typically. For your WOT pulls, they should be reading close to 1 volt, (1000 millivolts) because this indicates rich. If they are only reading slightly higher than cruise, in what I assume is a WOT pull, I would have a look at the wiring, or the sensors. Did you replace them with O2’s compatible with that PCM? Also, make sure they are hooked up to the right spot, because there is such a thing as upstream and downstream sensors, and they are indeed different. This could pose a problem too and is an easy mistake to make.
For the codes, unfortunately 99% of the time it’s a physical issue and not a tune. However, without seeing a log or tune file, tough to say really. The O2’s won’t help you for stalling, especially if the engine is flooding or what not because of shoddy readings. I can’t count how many threads are in this forum of similar problems because of bad O2’s. Typically exhaust leaks and super rich readings on one bank, etc, and the occasional flat lined one as you are describing. The shop that tuned it probably should of verified the wiring was right. Got to check the pins, PCM model, year, all of it to be sure. As I have found, P01 PCM’s don’t all have the same pin outs through the years, which is a real pain in the ***. Depends on what it was installed in in the first place.
For the codes, unfortunately 99% of the time it’s a physical issue and not a tune. However, without seeing a log or tune file, tough to say really. The O2’s won’t help you for stalling, especially if the engine is flooding or what not because of shoddy readings. I can’t count how many threads are in this forum of similar problems because of bad O2’s. Typically exhaust leaks and super rich readings on one bank, etc, and the occasional flat lined one as you are describing. The shop that tuned it probably should of verified the wiring was right. Got to check the pins, PCM model, year, all of it to be sure. As I have found, P01 PCM’s don’t all have the same pin outs through the years, which is a real pain in the ***. Depends on what it was installed in in the first place.
Thread Starter
Teching In
Joined: Mar 2007
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Another question I have is all along I have been ordering parts under a 2002 Corvette. I am replacing the 02 sensors but am curious if the sensors are for a 2002 corvette however the ECM is from a 2002 Camaro. Could that cause the issues I am having with the 02 sensors? They do have two different part numbers
