Sambo88

I have recently bought a 2002 impreza wrx estate and love the car but when the revs hit around 4000rpm under acceleration the revs dip back down then fly back up but seems to lose abit of power in this process. And then today the engine managment light came on. I have to wait till tuesday now as everywere is closed but just seeing if anyone has any ideas what it could be. Thanks

homebuiltracing

4000 limit sounds like a safe mode. Find yourself a bluetooth obd2 adapter and app for the phone to read the error codes. Knowing what triggered check engine light will help, before that you can hardly tell what's wrong, only guessing...

Sambo88

Thankyou for the reply the code which came up says that it is running to rich which i guess could be a number of problems po171

homebuiltracing

This code means too lean:

P0171 code definition

System Too Lean (Bank 1)
better don't push it too much until you find the problem.
may be fuel pump/pressure issue or some other stuff...

yabbadoo4

iTrader: (8)

p0171 means running rich OR lean. most common is a vaccum leak so check all pipes and hoses in case any have came off or are holed and letting in air. could also be a dirty or faulty maf sensor. you can clean the maf with some brake/carb cleaner its just a wire with some current running to it but they can get dirty and not read properly, youtube will prob have a video showing how to do it. could also be your front 02 sensor is faulty/bad. i think i read somewhere if you disconnect the maf and it runs better that might indicate the maf is bad so that might be worth a try also. if the car cuts out and stalls/dies i think that means the maf is probably ok. hopefully some of the other guys on here who are more knowledgeable can pitch in.

Sambo88

Thanks everyone great help as always i will check the maf sensor today as this is definatly worth a quick check. I have had a look for faulty pipes but doesnt seem the easiest engine to look around

Sambo88

So when i unplug the maf sensor while the engine running it continous to run but at about 1500rpm do we reckon this is worth changing it is very clean. Thanks

Gambit

iTrader: (6)

dont change the maf until you are sure you have no vacuum/boost leaks

MrRtm

What air filter are you running? When I bought mine it came with some k&n typhoon thing with a plastic cover on it, car ran like **** and thew up an eml because of it until I changed it for the spc one from my other car and all problems went away. Just a thought