2012 Trd Tacoma 4x4

So I have a question for you Toyota guys see if you can help me or have any ideas! Bought a 2012 tacoma 4x4 4.0 back in February from dealer with check engine light on! They said they would fix it and have taken it back to them 15-20 times them saying it’s fixed! They have replaced all injectors, fuel pump, gas cap, charcoal canister, spark plugs and the check engine light is still coming on! I’m lost..... Codes being thrown are emission codes 0440 0442 p445 0446

 

Welcome to TacomaWorld!

Might be a long shot, but check the fuel cap. If it is aftermarket, replace with OEM. If it is OEM, check the gasket and make sure it is intact with no cracks or anything. It may be not sealing properly.

 

OP, that is quite a grocery list of things that have supposedly been replaced. Have they been giving you receipts with those items listed?

 

Yes they have I have all receipts about 3,000 dollars worth of work with parts and labor!

 

They should be following the troubleshooting chart from the Toyota service manual to narrow down the issue with those codes. The first thing I'd do as a tech is smoke test the evap system to see if there are any leaks and if that shows nothing is continue to follow the troubleshooting flow chart. There are other parts within the evap system that can fail and cause those codes that you haven't listed as being replaced yet... Seems like they've been throwing parts at it this far. There is still the purge valve and solenoid among other things. I believe the very last thing on the list is the ECM itself but this sort of failure is rare.

Many times reasons for these codes are often as simple as a bad or poorly sealing gas cap or a vacuum line popped off somewhere. Make sure they replaced it with an oem cap, you can even put some Vaseline on the seal to ensure a good fit, make sure there is no debris on the filler area where it seals and make sure it is not deformed in any way.

Hopefully you have some agreement signed in writing with the dealer that they will fix this other wise I'd give them back the truck if they can't. Gonna be a pain if you can't pass emissions. If it's a Toyota dealer they should certainly be capable of fixing it.

If they have a history of this truck and when the code came up and or anything related was done or happened to the truck at the time it might also help to eliminate the cause.

 

What I suspect is that the leak is somewhere in the vacuum lines, which is being missed. It's much easier to just replaced the end parts but they need to replace the lines too especially after that many failed visits. You can't just replace a part, clear the codes and hand the truck back to you. The codes will reappear after x miles of driving if it wasn't truly fixed in the first place. Bring it back and have them change all the vacuum lines.

 

Go somwhere else, they're just throwing parts at it

 

My guess is secondary injection valve or pump. Very common on 2012 Tacos. Check engine light first is how it starts and limp mode later.

 

As long as they are replacing parts with no out of pocket cost to you under warranty, I'd keep going back to them. Yes, it's a pain in the butt but if you take it to another mom and pop shop, they will probably not hold true to the warranty. If you take it to a Toyota Dealership, they also might not hold true to the warranty if it was an after market purchase. Yes it sucks, but if they are replacing with OEM parts, I would still suck it up. Thats just me though.

-J

 

Is your Track light coming on also with the check engine ? if so put a new Toyota fuel cap on,NOT a aftermarket.

 

Yes it is TRAC light on too! They replaced the fuel cap.... don’t know if it was a Toyota one tho!

 

Is this a used car lot? Im not sure id want inexperienced guys needlessly replacing parts on my truck. Take it to somebody that knows what theyre doing and dont be afraid to pay some diag time

 

Been down that road,it needs to be a factory cap,NO aftermarket,yes the computer on these trucks are that sensitive.I had the very same problem until I put a new FACTORY cap on (after using an aftermarket) and my problem was solved.

 

It is a used car lot! Where I bought the truck with a warranty!

 

I’ll give it a try!

 

This is true, gas caps are not all the same. oem is always better when trying to narrow down evap problems

 

sounds like either your gas cap, purge valve, or are you filling up and squeezing every ounce of gas you can in to your tank cause that will cause these lights to come on also. i just went through the whole secondary air injection valves and these codes had nothing to do with that. its somewhere gas related.

 

No once the gas nozzle stops I hang it up.

 

It’s also the second charcoal canister. They put one in and it worked for a month than check engine light back on. They pulled the filter next to the canister and was plugged with dirt and also had water in the canister! replaced it with another new canister! And check engine light and TRAC back on

 

Pull the top off your injection pump. If the filter is in one piece and no moisture in there then the secondary valves should be fine. That will eliminate that as possibility.