Repeat 2197 and now 2195 codes, it's complicated

Looking for some trouble shooting advice here as the situation is a bit too complicated for my comprehension. I have been getting 2197 codes for about 9 months. I clear the code, it comes back, I clear the code and I complete a drive cycle, check the voltage (it matches the other side which has no code) and eventually comes back. Sometimes in as little as 50 miles sometimes over 500. Initially i thought "okay exhaust leak", that was correct. Post the dump tube at the junction for the URD exhaust I put on a small leak. Got it fixed. Cleared the code and it came right back. Even though the sensor matched on voltage, I changed sensor and guess what? It came back.

Okay maybe I have shit luck. Third sensor here we go. New sensor in. Cleared code, completed drive cycle and nothing for at least 500 miles. Check engine light tonight. Okay lets see, and now I am throwing 2197 and 2195 codes. Voltage at idle looked about 3.3. I am not too familiar with reading lambda or any of the other metrics I can pull so any advice would be helpful.

For the record, I have the Magnuson supercharger on there, high flow cats (secondary cat delete), yotaworks tune, and am running denso O2 sensors. Has anyone had this problem before or have any thoughts? I checked the MAF and it looks immaculate. Check for exhaust leaks by chance yesterday because I was getting paranoid about the tacoma "clunk" but couldnt find anything wrong (then found all the threads on it). Should I try and hammer down the pedal and see if I can record the voltage during the pull, or maybe is this a fuel pump issue and I am lacking backpressure so it is just constantly seeing lean? I am just kind of lost here and out of my depth on it. Any advice is appreciated.

 

How long has the s/c been on there? If you flash back to the Magnuson file does it still throw codes? What was the last mod you did before the faults started showing up?

 

@a2lowvw, supercharger has been on at least a year, maybe 14-15 months. If I try to flash the magnuson tune it will wipe the yotaworks tune and frankly the tune is what made the car fun to drive again. I am thinking now that you mention it, it was around the time I did the high flow cats and the second cat delete I started to see the codes. Had the values changed to reflect the vehicles (completely legal) offroad intent and use so I wont see the codes for the rear O2 sensors. I did have the original o2 leak at the back of the dump tube at one point and fixed that. As of yesterday its nice and tight still, wont move a strip of paper if I hold it close at the juncture and I cant feel or smell exhaust with it running and me under it.

 

Have you checked intake for leaks and fuel trims?

 

if you suspect there is still a leak find a shop with a smoke machine and you can hook it up to the exhaust and it will pressurize the system and if any leaks are present you will see small amounts of smoke from it.

 

@Vlady I do not see any obvious indicators of an intake leak (nuts missing or fluid seepage) but I will have to run a can around the bottom edge of the maggie to see. I just do not see how it would affect only one side continuously, but you are right and I should give it a shot today. As far as fuel trims, I am going to have to see if I can find some youtube videos on how to check that as I am pretty much a potato as soon as it comes to anything electrical.

 

@a2lowvw dude thats a solid idea. Thank you. I appreciate you guys' help.

 

@Strekcorp Your code refers to SENSOR 1 on both banks which is the A/F Sensor and not the O2 sensor. It will say O2 sesnor on DTC but sensor 1 is the A/F sensors. Its normal that they go bad overtime. You might want to try changing it and see how it goes. It would be the first sensor on the exhaust manifold FROM THE ENGINE.

 

@Mcbelen My mistake. I meant to write A/F sensor, I guess in my mind I see them as the same even thought they are not. I replaced with denso part

$138 234-9140 Oxygen Sensor

234-9140 after confirming fitment on toyotas parts website. The truck has 30k miles by the way, so I doubt 3 sets of sensors one one bank (4 total) and 1 replacement on passenger side is normal at this point, especially at this interval.

 

Toyota FSM calls to troubleshoot these areas (electrical, air, fuel, computer). Some sort of OBD tool with functions will be helpful. Good luck.

 

@Strekcorp, Kindly reach out to us through DM's and we'll try to fix the issue. I think we need to have your truck data logged just so we know what we are chasing. There is a lot of factors to consider for the issue you have, the data log would help to narrow down and rule out what and where we can do adjustments and/or fixing to resolve the issue you have. Reach out to @mZiggy or me so we can start our diagnostics journey. Thank you

 

@Mcbelen Thank you sir. Message sent

 

For the sake of posterity, following up on this thread. Took the advice of @a2lowvw and did a pressure tested on the exhaust with smoke. Found a few small leaks at the junction for the v band and pre-muffler but could not find any others. Took the whole exhaust off from the afe dumps at the engine back to the exhaust tip, changed every gasket and sealed everything with a fine bead of permatex wherever applicable. Tested again, no leaks. Tested the intake manifold up to about 4 psi with smoke and could not find any leaks. Ran a propane torch (off) around all the mating surfaces and lines with no change to engine speed, so called that good between the two. Then I installed an AFR wideband and boost gauge. Highest I have seen is 7 psi for a split second (which is odd) but mostly getting up to about 6 and I run out of road or nerve. Vacuum at idle -19 to -21 depending on how long the car has been sitting environment etc, but it holds steady and AFR's runs at 14.7 give or take .1 (idle or light throttle). Kept getting the code on one bank.

Took the car to Toyota. After some negotiations, they were willing to do a "diagnostic". I told them I just needed the high pressure fuel pump checked as @Mcbelen took his time to look through a mountain of data and had evaluated it all. He noted the high pressure fuel target was out of range in a specific portion of the trend. I showed them the attached photos for reference to illustrate the noted discrepancy between target and actual pressures. They were not impressed.


Toyota was kind enough to hold the car for 36 hours and report back to me that "Whoever had installed the supercharger had done it incorrectly". When I came in and inquired as to what they were specifically talking about they were referencing a found code "p066014 short to ground or open, intake manifold circuit" as well as the original stuck lean code. I showed them the instructions and on steps 121-122 page 35 of the install guide and informed them that this is the recommended procedure. They said they could not move forward with the diagnostic until this was addressed. I asked if they had tested the high pressure fuel pump as requested (no diagnostic was requested) they said "No" but that they could reschedule me but that they would have to make sure it was okay to work on the truck since it has been modified (which they knew when they took it in for initial high pressure testing).

I contacted Magnuson and ran all of this by them. Probably about 30 emails. They were incredibly helpful and assured me the installation was indeed as instructed. I cannot give them enough credit for helping me try to troubleshoot this. We tried to bypass the IAT breakout and still the codes returned. Re-tested intake and exhaust (no leaks, consistent vacuum, lines verified, heating circuit verified etc) and still the code came back. I ended up trending as much data as I could and found the following specifically when the codes developed,

Despite changing the sensors about 4 times so far ( 3x drivers and 1 x passenger) it seems that the issue may be in the response time for the affected bank or in resistance of the associated sensor. I bought another this time a different brand (up to 5 O2 sensors now in less than 10 k miles). Originally I had Denso, then I went to NGK and now back to Denso. This is now a Denso once again and I haven't seen the code return for about 4 days. The progressive high pressure pump waveform is still strange to me but AFR's look good and the truck is running fine. I do wonder if perhaps there needs to be an adjustment on the tune due to the reduced backpressure from the missing secondary's and hi flow front cats (since @OVTune had mentioned years ago that he had to adjust his tune for it) but doubt that is what is causing this issue. I will post a shorter update if the code returns. Thank you guys for all the help.

 

Glad to hear you are making progress. Hopefully the codes stay away