Ok, here is my issue. I ended up with a 2003 EVO (long story) with several missing parts. I parked it in my garage for about 2 years and finally started to rebuild it this past Spring. The car was finished in late April with minor cosmetic issues but drove fine. I replaced the clutch, intake system, CV axles, serpentine belt, blow-off valve, battery and the MAF sensor. However, I bought the MAF sensor on eBay that belonged to a 2009 EVO MR. About a month of driving the car almost daily, the SES light came on and I noticed that the car started acting sluggish. I took it to Advance Auto Parts to get the code which came back as a “Cylinder 1 Misfire”. I googled the code, read some posts on here and thought it was probably the spark plugs. I changed the spark plugs, coil packs and took the car in for an oil change. Nothing changed. SES light still on, car still driving sluggish. So, I took the car to the Mitsubishi dealership where it was purchased a couple years ago. They looked at it and said the injectors were fine (2 were clogged up but were cleaned) and so were the coil packs, but couldn’t get the ECU to throw any codes. Their suggestion to me was to get the car tuned which would determine if the ECU is working properly. I did tell them that the MAF sensor is from an MR and they said that tuning the car would help it greatly since it has so many aftermarket parts.

When I picked the car up from the shop, I noticed a rich fuel smell that penetrates all the way into the cabin. Also, my gas mileage has decreased; I now get about 10-12 mpg. The car is running better (I’m guessing from the unclogged injectors) but it does sputter and then gains power again (happens constantly while driving the car) . So, my question is do I get the car tuned or replace the MAF sensor first? (with one that belongs to an Evo 8). I wasn’t ready to get the car tuned just yet b/c I still want to add more upgrades to it but if that is my only solution, I will. I'm also getting a different code now which is P0300 (Random Multiple Cylinder Misfire).

I feel like giving up on the car. I am a point where I don’t know what to do or even where to take the car. I need as much help as I can get. Thanks to everyone in advance for helping.

 

I would start getting the supplies you need to pull some logs and see what the car is doing. Some helpful items would be an AFR gauge, Boost Guage, and Tactrix Cable. Next I would see a tuner to make sure everything is calibrated correctly.

 

Has anyone tried using the MAF from a different generation Evo before.

 

I know you can use MAP sensors and just recalibrate, not 100% about MAFs though.

 

I would start with the right maf. See if somebody will let you borrow one maybe? The stock ecu has a limp home mode if the maf fails, goes out of range (or you blow off a IC pipe and unplug the maf) to get you home or off a busy highway. It runs super rich and will not allow you to do any spirited driving.

 

I've read threads where others said the evo 8's and 9's maf's are diff even though the part # is the same.
Also that p0300 code is very common on even stock cars so may need to turned off with tuning.
Best idea would be get a Maf from an 8 and go from there, next find someone to pull the rom and see what's on it now, if you go to a reputable tuner, they will probably retune you later with your future upgrades at a discounted cost.
Good luck

 

I would just make the switch to Speed Density and be done with the MAF. I made the switch earlier this year and I could not be happier. Good luck with whatever you decide to do.

 

I would figure out whats causing the problem before attempting any tune, check for boost leaks, damaged wiring, exc. 2 years is enough time for rats to move in to your wiring, replace the maf with a known good unit first.

 

i have one from my 03 if you are interested! i PMed you let me know!

 

a 2009 evo maf is a evo X if im not mistaken? check your loom first, then as mentioned above for boost leaks as these wreck havoc with MAF's and buy a MAF for a ct9a they are all the same, if none of that fixes your issue just get a tune and convert to speed density you wont regret it