Check Engine Light - P0174, P0171, P0650, & C0281
Asked by Justin Jul 18, 2016 at 06:57 PM about the 2004 Chevrolet Silverado 1500 RWD
Question type: Maintenance & Repair
My engine light came on yesterday so I bought a Innova obd2 reader and
got the following codes:
P0174, P0171, P0650, & C0281
After reading the codes I performed a MAF sensor cleaning with the MAF
Spray. The light turned off and then after a couple stops and an hour later it
came back on with the same codes some say freeze frame and or pending.
Where should I go from here? If it's the shop I just like to be educated
before showing up, if you know what I mean.
7 Answers
Auto_Centric answered 7 years ago
Fuel mixture codes. Check engine light code, and ABS code First things have the upstream HEGOS changed then rescan.The two main signals controlling air fuel mixture are MAF and HEGOS that's it so simple.. TPS is third and is more of an open loop PCM (computer map running signal %) of throttle opening...Congratulations you're the first person since I started answering questions... APRIL 2016.. THAT HAS PURCHASED A SCANNER ! THANKS, GIVES ME HOPE, " I just like to be educated" BRAVO,1 out of thousands! Regards
Thanks! Had no clue what HEGOS stand for but after some googling I found HEGOS = "Heated Exhaust Gas Oxygen Sensor". I'm debating on doing this myself (I'm gessing it's about $200 or more for a shop to do this) but I don't have a way of lifting the truck so might be a little more fun for me. I found this video that gives me a clue of what to do: https://www.youtube.com/watch?v=aXu463XT8lk Looks like this is the part and best pricing I could find with fast shipping, I think I need two: https://www.amazon.com/Bosch-15895-Oxygen-Sensor-Fitment/dp/B004AGCC1K
Auto_Centric answered 7 years ago
Confirm (2) Bosch 15895 Oxygen Sensor part numbers, 4 wire sensors are the heated design. (HEGO) The A1 video is a good example of the install. Yes, a shop will charge approx $300 there are 2. that's labor only!
Make sure you have no vacuum leaks or air entering after the maf on the intake plenum. Popular places to leak are brake booster line and connection same for the pcv. Checking fuel pressure wouldn't be a bad idea.
Auto_Centric - I'm not sure but are the Bosch 15895 the same for up and down streams? I keep seeing the same part number used for both. Andrew - I'll give that a check, I actually have a tester on hand!
Auto_Centric answered 7 years ago
Yes, all listed as 15895's Up and Down steam , keep in mind the down stream's only monitor Catalytic Converter temps based on oxygen content ...they have NO active control on any system! The concept of heating an 02 sensor simply brings it online faster then just the exhaust gas temperature. Trivia a couple manufactures, Bosch and Denso supply the major of 02 sensors to the entire automotive industry.
Parts finally made it in, and the check engine light turned off over the weekend. I'm assuming it would still be best to replace the part either way.
