So I had a maf go out. Just changed it all warnings went off but ce light. So I did a ecu reboot. Did the trick. Worked perfect. Car ram like a dream. Smooth fast sonded great. The I'm driving home 2 days later and check engine comes back on and the shift is lagging and no acceleration between 2 and 3000 rmps. Wth happened? Any ideas or similar stories. Thanks

 

So....did you get the code read?

 

We can not begin to help w/o this code.

 

Initially read it as maf. That's why I changed it. But today the check light was off again. But still shifting weird. Going like 40 down the road and I hit it to gradually speed up it will Rev up to like 4000 and just sit there instead of shifting.

 

I'm thinking it's unlrelated to the MAF and may be a transmission issue.

But without the code, can only guess. I'd borrow a reader and scan the codes and pending codes and see if anything comes up

 

That's the thing. Last week before maf I never had a single Trans problem. Light just went back on I'm heading to get it read now. Let yall know in a few

 

Ok so just got back.
P0171 system too lean (bank 1)
So they said that's and oxygen sensor. And the check engine light was triggered in the rpm range and speed I was experiencing the lag. They said a bad oxygen combo could easily give the problems I have been having. What do yall think? Should I order a new oxygen sensor??

 

It could be O2 sensor, but there are two on that bank.

Could also be the result of a misfire situation or clogging fuel injectors or a few other issues.

Google "G35 P0171" and read some of the threads. Some ideas as to how to troubleshoot.

 

Too lean could be plenty of things, air/vacuum leaks are common. MAF could be, oxygen sensor as well.

This is a code you need to troubleshoot because if you throw parts at this it can get expensive. I had that fault but no obvious reason for it, because I tested and checked everything as well as other technicians. We all looked at fuel trims before and after, no issues figured it was something due to my aftermarket tune, i just disabled the code. I never did change the oxygen sensor like everyone suggested but it was reading correctly.

 

I had that code when my intake was loose. Check you intake connections.

 

Did you experience and lag in the gears or acceleration while the intake was loose?

 

did you figure it out? I�m having the same issue currently it�s throwing MAF , throttle , and crankshaft sensors. Car revs to about 4k before shifting in second and randomly will lose power while accelerating trying to pin point it before I start dumping a bunch of money . Cleaned MAF problem is still there though

 

Check the rubber "accordion" intake connection between the MAF and intake tube. If that gets torn it can cause all sorts of driveability issues. You can get a used one at a wrecking yard, the thicker neoprene ones from Z-1 Motorsports for about $40 or through the dealer you have to buy the whole intake assembly to get them and that's around $120.

 

What codes exactly.