S70 rough idle after MAF sensor cleaning,RESOLVED, new MAF

neworleans · Post by **neworleans** » 07 Jul 2013, 16:41

Hello,

Last week I scanned my S70 and read two codes P1171 and P0300. I've searched for some solutions and decided to start with cleaning the MAF sensor.

I pulled it out yesterday and cleaned it with a MAF cleaner, let it dry overnight and installed it back. After I installed it, the engine idles very rough, it runs like a motorbike, when I push the gas pedal the idle goes down and when I pull my foot off the gas pedal it goes up until 1000rpm.

Do you guys think I messed up the MAF sensor?

What would you guys recommend?

Thanks for any input in advance...

Post by **Ben850** » 07 Jul 2013, 16:51

What year S70?
ETM?

I see in your tag 2000, sorry. Still, original ETM?
Was O2 sensor/s ever changed?

neworleans · Post by **neworleans** » 07 Jul 2013, 16:56

It is 2000... The car idled fine before the cleaning. The ETS light has been on since I got the car which has been 2 years.

The ETM was replaced I think around 2006, the yellow label say it was made in 2005. I didn't replace any O2 sensors...

Teslacoilftw · Post by **Teslacoilftw** » 08 Jul 2013, 14:29

I don't know about 2000 but I just replacemed my MAF on my 98 Volvo GLT. I noticed 2 Small hoses running off the backside Air Tube about a Dime in Diameter. Each of them had popped off during the replacement and I noticed and Verified they where in fact put back on when Reinstallation of MAF. I'd suggust making taking another look for possible vacuum leak.

neworleans · Post by **neworleans** » 08 Jul 2013, 18:32

That is exactly what I did today after work, didn't see anything wrong with those small tube connections.
I think I am going to go ahead and get a new MAF sensor but not sure if I should get a cheap one on ebay for 20-30 bucks or pay more and get the OEM????

Post by **abscate** » 08 Jul 2013, 19:12

Ixneigh on the Cheap one IMHO. You can replace sensor only with Bosch at about 65 USD

Post by **JimBee** » 08 Jul 2013, 19:37

A couple of things you could try first.
Start the engine. Your revs are going to be erratic. You might be tempted to play with the accelerator to keep it running. Instead, just let it be erratic until it stalls, if it does. It might need to reestablish harmony with the ECU and it can't do that if your keep sending it pulses from the throttle position sensor.
If it doesn't straighten out on its own, you can test the MAF with a multi-meter. Instructions are here:
http://easyautodiagnostics.com/Volvo-MA ... est-c.html

Post by **abscate** » 09 Jul 2013, 03:23

Have a good look at the connector too. Make break connector a few times to make sure it's making good contact, all with engine and ignition off, of course.

neworleans · Post by **neworleans** » 09 Jul 2013, 09:22

I will do that tonight, now I am kind a wondering if I damaged the sensor while pulling it off from the air tube, I had to pull it hard but when I did that I grabbed the whole housing, really interesting... I also sprayed the maf cleaner to the socket where the connector goes in to...

I will check the connector and try to run it as JImBee suggested and see if it reestablishes harmony with the ECU.

neworleans · Post by **neworleans** » 19 Jul 2013, 23:12

Update,

First of all thank you all very much for posting here. After all, I ordered a new MAF sensor from FCP and installed it. The car runs like a champ now, the engine light went off as well as ETS light, it doesn't hesitate to accelerate anymore. I wish I had this done earlier. I thought I had a failing ETM issue because I had the ETS light on as well. This car never drove this good since I bought it. It had been at dealer for a few times for other repairs but they never addressed changing MAF sensor, I almost bought a new ETM and installed it, it would have been a big waste of money. Anyway. basically I had a failing MAF and by cleaning it, it made it worse so I had to buy a new one. So if you guys ever receive these two codes, it may be related to the MAF sensor. P1171 and P0300...