2005 Tacoma P0606 code help

I have a 2005 Tacoma TRD that first threw a CEL with a P0420 and P0430 code and I believe came on a day after I bent the exhaust pipe in the rear and ran the truck to empty. I replaced 3 different exhaust gaskets and all 4 of my 02 sensors with aftermarket MOCA sensor purchased on Ebay. I also cleaned out the throttle body, MAF sensor with electrical cleaner, changed out my cabin air filter and intake air filter in the process of “fixing” my truck.

After all of this, I have fixed the P0420 and P0430 codes and now I have a CEL with a P0606 code that I can’t figure out for the life of me how to fix. I have vacuum tested my exhaust system and visually checked all 02 sensor connections and wires/grounds are secure. In the past I have had 18mpg and now I’m at 15mpg.

Are these aftermarket sensors not making my ECM happy? Is there something else I’m missing that I should troubleshoot?

 

This is what my 02 sensor voltages read.

 

I've seen bad O2 sensors cause P060x codes to set on Toyota's, I'd get rid of the Ebay junk and put some genuine Denso (not Amazon/ebay specials) sensors in there.

 

These are my short term and long term fuel trims at idle.




Upstream and downstream 02sensors I purchased.

 

Fuel trims are pretty high (+18%) but you are using bottom of the barrel China junk sensors so...
There's no way your getting a quality O2 sensor for $15 or a quality AFR sensor for $30, I wish they would stop selling this crap. You probably took better sensors off than what you put in.

 

Oh no lol! I think bad sensors just might be the issue then. Thanks Dm93

 

I just don't trust any auto parts from Amazon/ebay especially electronic ones, people buy it to "troubleshoot" problems because it's cheap but there's a reason it's cheap. Often times they end up "building in"more problems firing cheap parts at problems than they started with.

I'd much rather do the right tests and know (or at least be very confident) a part is bad before replacing it. We have enough issues with bad new parts from parts stores anymore much less crap off ebay.

Srry for seeming ranty but I have to deal with the aftermath of cheap parts quite often and often times have to undo the parts cannon to find the actual problem.

 

I wonder if I could just clean up my old OEM sensors and reuse them. I think what caused my P0420 and P0430 was the exhaust leak, so maybe these sensors should be fine?

 

I don't see why not if they were working before, at least that will give us a baseline for troubleshooting.

Idk how many miles you have but if they have over 200k miles on them they are probably getting pretty tired though.

 

True. The truck does have 230k miles and I think they are stock.. probably best to buy some new ones

 

I threw in 4 new high quality Denso O2 sensors and the P0420/P0430 codes persist. I’m thinking maybe time to replace the cats?

 

Long term fuel trim are both at 11.7 and short term is at 3.9 and 3.1 when idling.


Do the O2 sensor volts seem to be reading correctly?

 

Looking at static AFR/O2 voltages is kinda meaningless, they are in the valid range but idealy you need to graph them over time under various conditions to verify they are working properly because the voltages are always changing.

 

Copy that, thanks

 

I do have an exhaust leak here. It’s after the O2 sensors, so I don’t think it would cause my CEL.. or could it?


Also I took out my cats and cleaned and flushed them out very well. Not much for contaminants. And still I’m getting both codes.

 

Nice job cleaning your cats!

I changed my PCV Valve and it help calm down my P0420. The code would pop up every other month or so. Now i can see on my scan tool that every other month the code is pending but hasn't lit the Check Engine light since.

I did get a P0606 recently and bought a new Denso 02 sensor but I haven't gotten around to replacing it. The code went away on it's own and hasn't come back so, that's how that goes sometimes....Another thing on my list for this summer. Good Luck!

 

Thanks! I just check my PCV valve and it rattles just fine and was pretty clean, but I’ll look into getting a new one just incase.

 

Exhaust leak that far downstream isn't gona affect anything, if the converters are dead (which they probably are) there isn't anything you can do to bring them back.
The downstream ones aren't monitored so no need to worry with those as long as they aren't plugged/restricted.

 

Got it, thank you