Hi all, thanks in advance for the help. I’ve been a loooooong time lurker here and pride myself on being able to dig up relevant info from this board and answer questions, but I haven’t found an answer to my specific question for today and wanted to pose it to the powers that be.
I’ve got a 2005 w/ 249k that has been my loyal companion since 2010. For the first 12 years of ownership it was primarily a highway vehicle. Over the last 5-6 years my driving habits have changed and the majority of my driving now is a mix of shorter highway commutes (6-15 miles) and city traffic.
For the last 18 months or so I’ve had recurring emissions related codes starting with a P0156 and P0430. I accordingly replaced both the downstream O2 sensors at an indy shop. For about 6 weeks that solved the issue, but then the P0430 returned. I dealt with that intermittently for several months before diving into the problem again. I found that the downstream sensors had not been replaced with Denso, as I requested, but with Bosch. Additionally, the MAF, throttle body, and fuel injectors were all cleaned and the gas cap replaced. I have since replaced all 4 O2 sensors with Denso parts. The P0430 returned almost instantly and I now have a P0420 as well. I can clear the codes, but they will return on the next trip in the vehicle without fail now. I have noticed no change in behavior in terms of power or smoothness over this time. The only other things I would note are:
1) I do feel like my MPG has dropped a bit - I hove around 11.5 with my driving whereas I feel like 5 years ago that might have been closer to 13,
2) sometimes, especially on colder or more humid days, the exhaust fumes on start can smell very slightly rice, and
3) I do have a coolant leak now (getting this addressed ASAP and checking levels every day, seem to loose about a 2 cups / week).
My city-based driving routine and mileage lead me to believe that I may have killed the cats, but given that it’s not a cheap replacement, I wanted to sanity check with y’all before doing so.
In summary:
Thanks!
I’ve got a 2005 w/ 249k that has been my loyal companion since 2010. For the first 12 years of ownership it was primarily a highway vehicle. Over the last 5-6 years my driving habits have changed and the majority of my driving now is a mix of shorter highway commutes (6-15 miles) and city traffic.
For the last 18 months or so I’ve had recurring emissions related codes starting with a P0156 and P0430. I accordingly replaced both the downstream O2 sensors at an indy shop. For about 6 weeks that solved the issue, but then the P0430 returned. I dealt with that intermittently for several months before diving into the problem again. I found that the downstream sensors had not been replaced with Denso, as I requested, but with Bosch. Additionally, the MAF, throttle body, and fuel injectors were all cleaned and the gas cap replaced. I have since replaced all 4 O2 sensors with Denso parts. The P0430 returned almost instantly and I now have a P0420 as well. I can clear the codes, but they will return on the next trip in the vehicle without fail now. I have noticed no change in behavior in terms of power or smoothness over this time. The only other things I would note are:
1) I do feel like my MPG has dropped a bit - I hove around 11.5 with my driving whereas I feel like 5 years ago that might have been closer to 13,
2) sometimes, especially on colder or more humid days, the exhaust fumes on start can smell very slightly rice, and
3) I do have a coolant leak now (getting this addressed ASAP and checking levels every day, seem to loose about a 2 cups / week).
My city-based driving routine and mileage lead me to believe that I may have killed the cats, but given that it’s not a cheap replacement, I wanted to sanity check with y’all before doing so.
In summary:
- Currently throwing P0430 & P0420 codes w/ no noticeable decrease in power or smoothness
- O2 sensors have been freshly changed with Denso parts
- MAF, throttle body, & fuel injectors recently cleaned and gas cap replaced
- perhaps suboptimal MPG & slightly rich exhaust at start up
- daily driving includes primarily city stop & go and shorter highway trips
Thanks!
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