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Good day. l just finished my second part of my build on my 03 Z06. My first part was longtubes with catless X-pipe into factory 2-1/2" Ti cat back, Dorman LS1-LS6 4 bolt 90mm
intake 615-901, stage one ported factory 243 heads. When finished and car was started, l got the usual lean codes and 02 codes as l am no longer using the rear 02's. Then, a week
later l tore the car down again and installed a BTR stage 2 cam, Melling oil pump, double roller chain, and new 34# injectors. Now when l start the car it is giving me a PCM P0106 MAP code issue which l researched and came up with the following P0106: Manifold Absolute Pressure (MAP) sensor signal not within predicted range for 2 seconds. Inspect for: - restrictions in the MAP sensor vacuum source - MAP sensor seal missing or damaged - vacuum hoses disconnected, lose, or incorrectly routed - intake manifold leaks - vacuum leaks at the throttle body.
After checking all these locations and finding no leaks, l figured l would go one step further and hook up my smoke machine, which after several moments of looking for smoke, revealed none. So l have no vacuum leaks, l purchased a new MAP sensor (china) and no different. l dont suspect this is the issue anyway as the code didnt appear until the cam and injectors were installed. The car does start and idle but as one would suspect is running very rich. l am going to set up a dyno tune for the car hopefully this week, (not easy here in Comiefornia) l just dont want to drop off a car with an underlying issue to be tuned. Can this code just be due to the car being so far out of tune now? Thanks in advance for any ideas/opinions
With those mods you have done that may be setting that DTC !!...a tune should remedy that....if you have a scan tool you can look at “desired” vs. “indicated” throttle position...those percentages are most likely far apart !!
P0106 means the MAP is failing its rationality test... IE at X rpm and Y TPS, there are min and max expected values. If you go above or below that, the CEL will trigger.
If you have a scan tool, I would do a scan with the engine off. Make sure MAP is accurate value and TPS is changing with accel pedal position. Usually a dead sensor or messed up wiring will trigger the "circuit low" or "high" codes...so the sensors are spitting out data, but something is off. Even a cheap ELM bluetooth OBD dongle and phone app should work for this.
If you're still on stock tune with all those mods, I guess it's possible it's just running very poorly such that it's outside expected values. If you do the above stuff and everything seems to be working right, I would just press to tune.
Here's the min/max rationality test tables for reference:
Thank you Aaron for reply. So see if l can get a scan tool it should have those parameters already? l am suspect that it is actually wiring or a sensor as previously mentioned, this code for the MAP sensor did not appear until l installed the stage 2 BTR cam and larger 34# injectors. All the wiring is the same and in most cases wasnt even touched to remove the install cam and injectors. Before the cam and injectors went in l drove the car several miles on several different occasions and no P0106 code. So it does seem unlikely that one or more sensors just happened to fail after that and or wiring somehow got effd up. But, l'm not beyond accepting this may entirely be possible either so l will indeed try and check with a scanner.. Thank you again
Thank you C5. l think l will need to procure a scan tool. But will they (scan tool and or software) have both those parameters built into it?
I’m pretty sure any scan tool other than a “code reader” should show these data PIDS...to tell you the truth EVERYONE that owns a C5 or any other 20 year old car who does there own maintenance should have one in their tool box...I myself have 4 scan tools...Snap On Verus Pro, Tech 2, Autel MS906, and a factory scan tool for my DD Toyota 4 Runner...they make diagnosing so much easier. All of my scan tools are “bi-directional” which means I can turn on cooling fans, energize solenoids, and a lot more...I don’t know what your budget is but the Launch X431 mini looks like a nice small bi directional scan too !!...I’d say let your tuner have a go at it and have him look at those data PIDS...also anytime you see a DTC that’s says “circuit high or low” the problem is likely a wiring issue !!
I’m pretty sure any scan tool other than a “code reader” should show these data PIDS...to tell you the truth EVERYONE that owns a C5 or any other 20 year old car who does there own maintenance should have one in their tool box...I myself have 4 scan tools...Snap On Verus Pro, Tech 2, Autel MS906, and a factory scan tool for my DD Toyota 4 Runner...they make diagnosing so much easier. All of my scan tools are “bi-directional” which means I can turn on cooling fans, energize solenoids, and a lot more...I don’t know what your budget is but the Launch X431 mini looks like a nice small bi directional scan too !!...I’d say let your tuner have a go at it and have him look at those data PIDS...also anytime you see a DTC that’s says “circuit high or low” the problem is likely a wiring issue !!
Got it! Sounds good and l will indeed invest in a good scan tool. Thank you for the help sir!
Thank you Aaron for reply. So see if l can get a scan tool it should have those parameters already? l am suspect that it is actually wiring or a sensor as previously mentioned, this code for the MAP sensor did not appear until l installed the stage 2 BTR cam and larger 34# injectors. All the wiring is the same and in most cases wasnt even touched to remove the install cam and injectors. Before the cam and injectors went in l drove the car several miles on several different occasions and no P0106 code. So it does seem unlikely that one or more sensors just happened to fail after that and or wiring somehow got effd up. But, l'm not beyond accepting this may entirely be possible either so l will indeed try and check with a scanner.. Thank you again
Yeah there's obviously a huge array of scan tools and their prices vs functionality. But in this case, even a cheapy ebay $15 bluetooth dongle and phone app would suffice because it can see RPM, TPS and MAP. I have a relatively cheap BT OBD dongle that I keep around as a simple code reader and scanner.... it's good for most basic diagnosis and have used it to help friends out or will keep it in the car for a trip or something. But otherwise it's not a full blown setup obviously with various shop functions/tests etc. But I have EFI Live which does have many bi directional functions, should I ever need it on this car.
I’m pretty sure any scan tool other than a “code reader” should show these data PIDS...to tell you the truth EVERYONE that owns a C5 or any other 20 year old car who does there own maintenance should have one in their tool box...I myself have 4 scan tools...Snap On Verus Pro, Tech 2, Autel MS906, and a factory scan tool for my DD Toyota 4 Runner...they make diagnosing so much easier. All of my scan tools are “bi-directional” which means I can turn on cooling fans, energize solenoids, and a lot more...I don’t know what your budget is but the Launch X431 mini looks like a nice small bi directional scan too !!...I’d say let your tuner have a go at it and have him look at those data PIDS...also anytime you see a DTC that’s says “circuit high or low” the problem is likely a wiring issue !!
l found this one on Amazon for $45,
LAUNCH X431 OBD2 Scanner Creader V Plus Car Code Reader Diagnostic OBDII Leak Detection Tool
is this the one you referred to? lt says its bi directional
PCM code P0106 MAP
