Hey guys I've been trying to figure out a problem with my 2002 max for the past couple weeks. At wot the car goes into flail safe mode, and when it does the car is barely driveable - not even 30mph. I checked for the codes and there isn't any just one for the reverser sensor. Recently I've replaced the maf sensor with the 2001 maf mod. Could this be my problem? It's done this before I changed it but never went away. I have no cats and o2s have spacers. Any ideas?
Car has the following - obx headers, intake, afc, nwp spacers. Thanks.

 

the what? What was the code #?

 

p1706

 

park/neutral position switch. I can imagine that if the ECU is not sure whether youre in the right range for D or R and youre at speed it might throw a hissy fit over that. Have you looked into that? Its easy to diagnose whether sensor or wiring issue and not an expensive fix. That would be my first stop.

 

It's a manual transmission. I'll be looking into it tomorrow but I doubt it's a wiring issue because I've never messed with the wiring. Any more suggestions?

 

if its manual that code isnt related, I have had that from time to time with a sensor issue and its never caused a problem. I assume you added in the temperature resistor from your 02 on the side of the 01 MAF? Ive never heard of going into safe mode without a related code

 

I did I even made sure and crimp in the ends for good contact :-\

 

how many times have you had limp mode? I hate to suggest doing it again since you dont know why its going into limp mode, but checking after getting limp mode once or twice more for a code might be useful

 

The MAF is a good possibility and worst of all, they don't always throw codes.

 

this is why modern ECU engines are a blessing and a curse. It can save your butt going into limp mode and then tell you whats wrong making diagnosis a snap, or it can go into limp mode for basically no reason or a faulty reading and then not tell you whats up, leaving you to chase your tail. My new car goes into limp mode if you push the car hard before oil is up to temp (saves turbo seals) but it doesnt tell you that is why

 

I feel like that's the only option I have left is to keep doing it until something shows up. Might have to change my plugs after due to fouling out

It's still a possibility, so I'm looking around right now to see if I can find an am600

The main reason why I prefer older cars!

 

For clarification, the MAF will cause fail-safe, which is different than limp mode and only shows up in 02-03 models with electronic throttle. MAF/Fail-Safe you can at least go t work/get around and go say about 60-65 MPH. I used to have an intermittent problem with it and it turned out it was my AFC and it's throttle position sensor ground, so I decided to double ground the ECU grounding "jacket" using grounding wires from Lowe's. I would check your codes again because typically limp mode is related to TPS. Although the IVT's are supposed to trip that mode too, I don't think I've ever heard of it. I've had IVT codes but it never went into limp mode. Also, AT's go into it when the CAN lines from the tranny or the VSS, but since you're MT, those don't count.

 

I think you maybe onto something there. I'll check all my grounds and maybe even remove the afc. Thanks for the help.

 

yeah youre right the MAF usually causes the well known 2800ish RPM rev limit and thats always a good indicator of an MAF issue although Im sure there are other causes.

On a side note I did trip a true limp mode with the MAF signal once, messing around with VAFCII setting while the engine was running. It didnt like one of the changes I made and threw a hissy fit.

 

I've done that numerous times with the MAF/SAFC usually forget to connect the MAF, and have yet to get limp mode. Mine was always related to the TPS/CAN lines/tranny TCM stuff.

 

Of those Ive only got the TPS. I guess you have to really screw it up to get there

 

Yup! Although there are lots of callouts in the FSM, I imagine if there was some dual event that occurred voltage wise, it could happen re: MAF/IVT/TPS/APPS etc. I think limp mode can be dangerous. I was crossing an intersection one time when it happened to me.

 

Thought I should update. Ended up being the illusive and pesky knock sensor -_-

 

How did you verify/confirm?

 

I replaced it with a spare I had. Did this after replacing all my grounds