My non-turbo Impreza has started cutting out occasionaly. So with the help of your advice, I reset the error codes, ran the car to work (it cut out twice on the way) and then read the codes. I got 23 which is the MAF sensor or circuit. A new one is £340 (ouch), and alternatives are not available for this one. I measured the voltages at the sensor and got 0.25V with the engine off. 1.25V with the engine on, reducing to about 1V as it all warmed up. What worries me is that I may have a bad connection somewhere and replacing the MAF wont fix it! Any advice from you experienced people out there would be appreciated. The car has done 102000 miles and this is the first thing that has needed replacement. Brilliant in my view!

 

JohnD.

It definitely sounds like a MAF related issue. I had similar issues with my legacy.

 

As for the wiring or the MAF sensor, you can try testing the wiring, but with intermittant problems, it's a little more difficult to get an accurate test.

 

Do you know anyone that has a similar car or another subaru of the same year that you could maybe swap the MAF sensor to test?

 

Other option would be to try and find a used one. As you found out, replacing the MAF sensors with new ones is expensive.

i just replaced mine. 96 legacy.

 

it was doing the same thing. eventually (i was lucky this happened in the garage) your engine won't turn on at all.

if it's a hot wire anemometer type MAF it'll have very tiny hair-thin wires located within the airflow. if one of these tiny strands breaks it can cause driveability issues. pull the sensor and just look through it into a light. a broken strand will indicate a bad sensor for sure.

 

get a used one and swap it in.

i have a used MAF i'd sell you for way less than 300 pounds...whatever that is!!!

Thanks Guys.

$500!!

JohnD

$500, that's insane alright. get a used one (or two).

$500, that's insane alright. get a used one (or two).

 

i dont remember how much mine was....around that i think. but i'm happy that i got a new one from Fuji so i know itll work for the long run.

JohnD, you stated what I assume is the output voltage of the sensor. Did you check the input supply voltage also when you did this?

I paid $10 for a used one, and then like $75 for one at a junk yard when I really needed one. I keep the $10 one around incase I need a new one.

 

My gas mileage went to *************** when mine died...dropped to like 14mpg.

I paid $10 for a used one, and then like $75 for one at a junk yard when I really needed one. I keep the $10 one around incase I need a new one.

 

My gas mileage went to *************** when mine died...dropped to like 14mpg.

 

yeah, mine went from 17mpg to 24mpg after i switched it out for a new fuji one

Check eBay, I was just doing some browsing and I saw a couple of MAF sensors there.

JohnD, you stated what I assume is the output voltage of the sensor. Did you check the input supply voltage also when you did this?

 

I checked all 4? voltages with respect to the battery terminal. They were all zero except for the one that I quoted. Battery voltage was the usual 12 to 14 volts.

 

John.

i dont remember how much mine was....around that i think. but i'm happy that i got a new one from Fuji so i know itll work for the long run.

 

Fuji? That sounds interesting! Are they better or non standard?

I opened mine up and found broken solder joints on my 1990 legacy. resoldered them and everything was fine.

I checked all 4? voltages with respect to the battery terminal. They were all zero except for the one that I quoted. Battery voltage was the usual 12 to 14 volts.

 

John.

 

You stated that the 4 voltages were measured with respect to the battery terminal. I assume you mean the negative terminal or ground of the car system.

 

I don't have any reference material right now to look at but I think there is a problem here. I believe there should be at least 5 volts or maybe 12 volts on one of the leads going to the MAF, possibly provided from the ECU. Do you have a manual to check that?