P0037 and P0038 Simultaneously

[ryan2.3]

Pulled these DTC's with Torque and my BT Dongle

Vehicle VIN: JM1BK143641157917
Vehicle Manufacturer: Mazda
Vehicle Calibration ID: L373ED020L3V5020

Current Fault Log
------------------
P0037: HO2S Heater Control Circuit Low (Bank 1 Sensor 2)
P0038: HO2S Heater Control Circuit High (Bank 1 Sensor 2)


Been throwing both a P0037 and P0038 together for the last week. Gas mileage has gotten terrible. Light came on after 300km. I usually get to 500-550. have only been doing my daily commute all week. However, i haven't noticed much of a difference as far as how it drives. a few hesitations when i tried to really get on it (quick merges because MI on ramps are so short)

Upstream was replaced 3 or 4 months ago. I'm thinking i need to replace downstream, which i guess wouldn't be too bad; Bosch OE replacement (13770) is only $40 (20% off coupon on amazon). But i was hoping for a second opinion because i found a couple threads where replacing didn't help. Also, most threads people had one or the other, not both... and before asking, they're not history codes. I cleared them and after a day they both came back together at the same time.

[S.F.W.]

Have you replaced the purge solenoid previously ?

[ryan2.3]

i didn't replace it, but i did adjust the set screw in it 3 or 4 months ago hoping it'd help with a different issue i was having

[S.F.W.]

i didn't replace it, but i did adjust the set screw in it 3 or 4 months ago hoping it'd help with a different issue i was having
You are going to need to replace that at some point.

This issue seems to the the downstream need changing

[ryan2.3]

yeah, i was just trying to delay it for a bit. But I just found it for $16 on amazon. So I think i may just do both at once

i'll report back in a few days after it arrives and i get it installed.

Thanks,

[MK519]

yeah, i was just trying to delay it for a bit. But I just found it for $16 on amazon. So I think i may just do both at once

i'll report back in a few days after it arrives and i get it installed.

Thanks,

mind sending me that link? ryan2.3

[ryan2.3]

http://www.amazon.com/gp/product/B003P9YJSM?psc=1&redirect=true&ref_=oh_aui_detailpage_o00_s00

My mistake.. the 702 was $16, this was $24. I know it says mazda 6 and that it won't fit mazda 3, but one of the comments said that they used it on their 2005 mazda 3, so i figured i'd try it. It'll be here Monday so i can install it and confirm

EDIT
here's teh downstream i picked up.. there's a coupon to "clip" under the price so it was $40

http://www.amazon.com/gp/product/B000CF1VC4?psc=1&redirect=true&ref_=oh_aui_detailpage_o01_s00

[ryan2.3]

so swapped them in.

just to confirm, the Dorman 911-701 even though it says will not fit my 2004 mazda 3 according to amazon, it was a perfect fit. the rubber ring also slipped right onto the mount cilp. Hopefully this takes care of the P0446 i was also getting.

I installed that and the O2 sensor. We'll see if the codes come back. They were coming back every day or two, so i'll update in a week because i should know for sure by then