P11EE00 P160500 codes

Had check engine light came on around 86,000 miles took it to a local shop and they said it was a misfire in cylinder 3 so I bought a new coil pack and replaced the spark plug and coil the light went off for a few days but came back so I took it to my local dealer this is what they determined.
CHECK ENGINE LIGHT ~|~CUSTOMER STATES CHECK ENGINE LIGHT ON AUTO SHOP SAID MISFIRE IN CYLINDER 3... CHECK AND ADVISED ~|~P11EE00- CYLINDER 3 AIR-FUEL RATIO IMBALANCE (PORT), P160500 ROUGH IDLING. VERIFIED CONCERN, TEST DROVE A OBSERVED MISFIRE MONITORS, CYLINDER 3 MISFIRED 2-3 TIMES. SWAPPED IGNITION COIL 3 AND 5 AND TEST DROVE AGAIN AND DID NOT MISFIRE. ALSO PERFORMED STAL ~|~PERFORMED INJECTOR CLEAN SERVICE, CLEARED DTCS AND TEST DROVE. VEHICLE RAN BETTER, DID NOT MISFIRE NOR DID ANY CODES APPEAR.

 

Increasingly talked about problem as more and more of them pop up. The typical fix is installing another loaded cylinder head as a replacement which comes with valves in it.

I’m going to guess the issue comes back soon again. So far these codes have a 100% rate of needing a new head. None of the other “possible causes” (coil pack, spark plug, injector, yada yada) have been the fix in any of the threads I’ve seen.

 

Guess I will find out in a few more days if the light comes back on. The thing is the truck seemed to be running fine I couldn’t feel it skipping I do have a lifetime power train warranty from the dealer.

 

Welcome to TacomaWorld

 

so what is the actual problem is the head or valve not sealing during combustion?

 

Nobody really knows.

 

Still a mystery it seems. There’s a recent thread about this with mention of the injector getting dirty producing a lean mixture and burning the valve. Sounds more logical to me than the “manufacturing defect” theory that’s wildly popular as it doesn’t seem to be happening to the Lexus and others and I’d expect a defect to show up a lot earlier, but who knows.

 

I had the 2012 Pilot with the 3.5 v6 and they had a issue with the cylinder rings shrinking and allowing oil to bypass and cause fouling of the plugs if I remember right I think it was also cylinder 3 they did a recall on those.

 

Welcome to TW!

 

So just found this TSB for Lexus
https://static.nhtsa.gov/odi/tsbs/2021/MC-10190467-9999.pdf

 

Update
I hit 91,000 miles and the check engine light came back on I’m going to take it back into the shop on Monday11/21/2022

 

Technician said it still had a fuel air ratio imbalance. I asked them to check the cylinder and exhaust valve but they didn’t they want me to replace the injector. They cleared the code but it came back on and now it’s off again. Truck is running smooth. I’ve ordered a bore camera so that I can inspect the cylinder myself I’ll give an update when that happens.

$50 DEPSTECH Industrial Endoscope, 5.5mm 1080P HD Digital Borescope Inspection Camera 4.3" LCD Screen IP67 Waterproof Snake Camera with 6 LED Lights, 16.5FT Semi-Rigid Cable,32GB Card and Helpful Tool

https://www.amazon.com/gp/aw/d/B094XGX6GQ?ref=ppx_pt2_mob_b_prod_image

 

Just got the compression test done looks like cylinder 3 is only at 130 supposed to bearound 190

 

Just got the quote from my Toyota dealer today new cylinder 3 around $7000

 

Thanks for the update. Sucks these are happening more frequently. Too often for me to ever want a 3.5L Tacoma again.

 

I got the dirty injector explanation too, both on this forum and from the dealer but I think that's a false flag. These engines utilize what is known as the Atkinson cycle when means the intake valve is partially open during combustion and that makes the injector look dirty leading mechanics to think it's the cause of a burnt valve. The information I got from the regional rep is that Toyota has changed the machining of the head to eliminate the problem. I don't have a date for when the change has been implemented other than that it's fairly recent but we won't know if that does in fact correct the problem until newer models don't experience it nor do those with more recent head replacements.

 

I’m at 92,000 miles now and I’ve opened a case with Toyota to see if they will cover the work I’m hopeful they will if not I’m just going to trade it in.

 

https://www.tacomaworld.com/threads/take-it-back-to-the-dealer-from-where-i-got-it-or.796080/page-4
same code, I was quoted $4k, covered under warranty after producing proof of maintenance
Repair completed in 4 days. Rental was provided, N/C.