I had the "Service Engine Soon" light on for the last 3 months. It also comes with the code P171 and 174. I am in Toronto and now winter comes. Temperature drops below zero. At the same time, the light goes off !!!

Any guru here heard before MAF has something to do with weather?

My truck is 2001 DII with 135k. My MAF is 4 months old from eBay. Brand is not Bosch. The light stays on since I put on this new (+ junk)MAF.

 

Sounds like you just need to move further north so that it stays off all the time.lol
Check your connection, it may not have been seated properly and when it got cold it shrunkand then made the proper connection.
I could be totally wrong, but its worth a shot.

 

MAF sensors use a heater grid or hot wire. The colder intake air is possibly having an affect on the operation of the "hot wire". If you are confident the MAF is to blame, I would replace it. If your p0171, p0174 is accompanied by 3rd and/or 4th gear ration monitoring faults stored in the transmission control module, then waste no more time and replace the MAF sensor soon.

 

The cold weather won't cause the MAF any grief as long as it doesn't get moisture in it.
Too bad you didn't buy a new Rover replacement with a 1 year warranty.

 

Doesn't always pay to buy cheap.Especially when the oem part at the dealer doesn't cost much more. Should always check with your parts counter before buying aftermarket. I'm sure you'll be in for pleasant surprises from time to time.

 

Thanks everyone. I think I will replace it .... but after this winter.

 

I wouldn't let both banks run lean all that time during the winter, change it out now, it only takes 5 minutes to do, you'll also regain some of your mileage and performance those codes are costing you.