Change HistoryDiscussion of Boxsters and other Porsches |  |  |
Expect the best, and accept no substitute. |
Products for your Boxster, Cayman and Carrera. |
 | |
Message: The MAF is certainly worthy of suspicion. Shade tree mechanic trick is to disconnect the MAF...
Changed By: MarcW
Change Date: July 13, 2014 11:32AM
The MAF is certainly worthy of suspicion. Shade tree mechanic trick is to disconnect the MAF...
Change Date: July 13, 2014 11:32AM
The MAF is certainly worthy of suspicion. Shade tree mechanic trick is to disconnect the MAF...
at the wiring harness and clear the codes -- to reset the adaptation values to their defaults -- and then drive the car to see if the previous behavior and error codes return.
Then after a 30 mile drive or so -- enough of a drive to give the DME time to go through all readiness monitor tests -- reconnect the MAF, clear the codes again, and test drive the car again. The results of this then can help you condemn the MAF or prompt you to look elsewhere.
There are enough readings out of whack but some might be wrong collaterally.
Tell me about the car? Are you running an aftermarket air filter? What is the history of the car? How old is the AOS? I've gone through more AOS's than MAF's with my 02 Boxster. In fact I've gone through as many oil filler tube caps as MAF's. I replaced what proved to be a perfectly good MAF when the real problem was a leaking oil filler tube cap. When the replacement MAF failed after maybe nearly 100K miles I installed the original MAF -- which thankfully I saved -- and it worked fine and has continued to work just fine since.
Another shade tree mechanic trick is to try to unscrew/remove the oil filler tube cap with the engine idling. While the cap should unscrew just fine you may find you can remove the cap against the pressure difference inside and outside the engine due to a bad AOS that has subjected the crankcase to extremely low pressure. However, even if you are able to remove the cap without undue difficulty this doesn't let the AOS off the hook.Enough have failed and not manifested this behavior that the AOS would not be entirely eliminated if the cap came away without a struggle.
While either the MAF or the AOS could be at the root cause of the engine's behavior I can't advise you to replace either item based on what you have posted.
BTW, I did a search for P1150 and P1120 and these error codes do not pop up at all for Boxsters. I visited renntech.org and these codes are not in the data base of error codes for the early Boxsters.
Are you sure about the numbers?
P1531 -- camshaft adjustment for bank 1. I can tell you when the VarioCam sensor/actuator on my '02 went bad this was a pending code. The engine wasn't running very well. I did check fuel trims and noted one bank's were quite erratic. The tech later told me that it was due to the DME attempting to get the O2 sensor readings from the bank it wanted to get and had this continued the bank could have misfired as the mixture got too far off. It could be possible in your car's case the underlying problem is bad VarioCam solenoid or actuator and the other readings/error codes arise from that.
But like the MAF and the AOS I can't advise you to replace the solenoid/actuator. These are quite expensive and costly to replace. It cost me around $3K to replace both in my Boxster.
Then after a 30 mile drive or so -- enough of a drive to give the DME time to go through all readiness monitor tests -- reconnect the MAF, clear the codes again, and test drive the car again. The results of this then can help you condemn the MAF or prompt you to look elsewhere.
There are enough readings out of whack but some might be wrong collaterally.
Tell me about the car? Are you running an aftermarket air filter? What is the history of the car? How old is the AOS? I've gone through more AOS's than MAF's with my 02 Boxster. In fact I've gone through as many oil filler tube caps as MAF's. I replaced what proved to be a perfectly good MAF when the real problem was a leaking oil filler tube cap. When the replacement MAF failed after maybe nearly 100K miles I installed the original MAF -- which thankfully I saved -- and it worked fine and has continued to work just fine since.
Another shade tree mechanic trick is to try to unscrew/remove the oil filler tube cap with the engine idling. While the cap should unscrew just fine you may find you can remove the cap against the pressure difference inside and outside the engine due to a bad AOS that has subjected the crankcase to extremely low pressure. However, even if you are able to remove the cap without undue difficulty this doesn't let the AOS off the hook.Enough have failed and not manifested this behavior that the AOS would not be entirely eliminated if the cap came away without a struggle.
While either the MAF or the AOS could be at the root cause of the engine's behavior I can't advise you to replace either item based on what you have posted.
BTW, I did a search for P1150 and P1120 and these error codes do not pop up at all for Boxsters. I visited renntech.org and these codes are not in the data base of error codes for the early Boxsters.
Are you sure about the numbers?
P1531 -- camshaft adjustment for bank 1. I can tell you when the VarioCam sensor/actuator on my '02 went bad this was a pending code. The engine wasn't running very well. I did check fuel trims and noted one bank's were quite erratic. The tech later told me that it was due to the DME attempting to get the O2 sensor readings from the bank it wanted to get and had this continued the bank could have misfired as the mixture got too far off. It could be possible in your car's case the underlying problem is bad VarioCam solenoid or actuator and the other readings/error codes arise from that.
But like the MAF and the AOS I can't advise you to replace the solenoid/actuator. These are quite expensive and costly to replace. It cost me around $3K to replace both in my Boxster.
Original Message
Author: MarcWDate: July 13, 2014 11:21AM
The MAF is certainly worthy of suspicion. Shade tree mechanic trick is to disconnect the MAF...
at the wiring harness and clear the codes -- to reset the adaptation values to their defaults -- and then drive the car to see if the previous behavior and error codes return.
Then after a 30 mile drive or so -- enough of a drive to give the DME time to go through all readiness monitor tests -- reconnect the MAF, clear the codes again, and test drive the car again. The results of this then can help you condemn the MAF or prompt you to look elsewhere.
There are enough readings out of whack but some might be wrong collaterally.
Tell me about the car? Are you running an aftermarket air filter? What is the history of the car? How old is the AOS? I've gone through more AOS's than MAF's with my 02 Boxster. In fact I've gone through as many oil filler tube caps as MAF's. I replaced what proved to be a perfectly good MAF when the real problem was a leaking oil filler tube cap. When the replacement MAF failed after maybe nearly 100K miles I installed the original MAF -- which thankfully I saved -- and it worked fine and has continued to work just fine since.
Another shade tree mechanic trick is to try to unscrew/remove the oil filler tube cap with the engine idling. While the cap should unscrew just fine you may find you can remove the cap against the pressure difference inside and outside the engine due to a bad AOS that has subjected the crankcase to extremely low pressure. However, even if you are able to remove the cap without undue difficulty this doesn't let the AOS off the hook.Enough have failed and not manifested this behavior that the AOS would not be entirely eliminated if the cap came away without a struggle.
Then after a 30 mile drive or so -- enough of a drive to give the DME time to go through all readiness monitor tests -- reconnect the MAF, clear the codes again, and test drive the car again. The results of this then can help you condemn the MAF or prompt you to look elsewhere.
There are enough readings out of whack but some might be wrong collaterally.
Tell me about the car? Are you running an aftermarket air filter? What is the history of the car? How old is the AOS? I've gone through more AOS's than MAF's with my 02 Boxster. In fact I've gone through as many oil filler tube caps as MAF's. I replaced what proved to be a perfectly good MAF when the real problem was a leaking oil filler tube cap. When the replacement MAF failed after maybe nearly 100K miles I installed the original MAF -- which thankfully I saved -- and it worked fine and has continued to work just fine since.
Another shade tree mechanic trick is to try to unscrew/remove the oil filler tube cap with the engine idling. While the cap should unscrew just fine you may find you can remove the cap against the pressure difference inside and outside the engine due to a bad AOS that has subjected the crankcase to extremely low pressure. However, even if you are able to remove the cap without undue difficulty this doesn't let the AOS off the hook.Enough have failed and not manifested this behavior that the AOS would not be entirely eliminated if the cap came away without a struggle.