unseen

whats goodie fam? its been a minute since i been on here, but i know i can return to my old tC family and get help when i need it. so long story short: i hydrolocked my engine which caused me to say screw it and i was done with my tC. toyota played me, and put a crate engine in it. after receiving the whip, i gave it to my little brother and bought a tacoma. it started to kick on CEL codes, of which toyota would not service because it wasnt part of the limited and shorterm "warranty." i moved away and couldnt help him take care of the car, while he showed it no love and has driven it till today with the codes. Inspection is up, and obviously wont pass till i get this taken care of.
im pretty sure all if not some are due to the bank1 and 2 sensors. im also sure theyre fried by now, but dont want to replace 1 or both of them to alleviate a code or 2 only to have it burn out again before i get rid of all codes. so can anyone direct me down the right path towards taking care of this issue? i appreciate all feedback. good looking out.

PO 171: system too lean (bank 1)
PO 441: Evap Emission Control, System Purge Flow Fault
PO 445: Evap Emission Control, System Purge Flow Fault Leak

Un4Scene

First things first - This is an emissions problem. As such, it should have a longer warranty than the rest of the car - 8 years/80,000 miles I believe. I'd check your paperwork to make sure, and if I'm right then talk to your dealer about it again.

Ugh. I hate emissions problems, but I'll give this a shot. The codes alone are not enough to diagnose a specific problem, but they can narrow it down a lot. P0441 and P0445 are far more common than they should be on Toyota 4 cylinders. The ECU periodically runs a diagnostic check on the emissions system. If a problem occurs then it throws the P0445. That code just means that the ECU couldn't complete the diagnostic test. P0441 means that you have a leak in the evap system which can be caused by everything from a bad gas cap to a clogged charcoal canister to a leaking vacuum line.

P0171 is a little more specific, but not much. If the engine is running lean then you either have too much air, or not enough fuel. I would start by checking all the lines for vacuum leaks, and looking at anything they're connected to for cracks or broken pieces. There's also a very easy way to check the brake booster: With the car turned off, pump the brake pedal until it gets as firm as possible. (If it doesn't get hard, or if it gets hard and then gradually drops with the engine still off, then you've probably got a bad master cylinder, or a hydraulic leak somewhere else) While holding pressure on the pedal, start the car. The pedal should drop some. If it doesn't, then you've got a bad power booster. By "bad power booster" I mean it's leaking vacuum.

If you can't find anything obvious in the vacuum system, then check the MAF and the air filter. Get some MAF cleaner or electronics cleaner for the MAF, and make sure the air filter isn't too dirty, wet, or oily.

That's about all I can think of for the cheap and easy solutions. Anything beyond that will require diagnostic equipment to be hooked up to the car.

The real PITA part of this is that once it's fixed the code will not clear until the ECU runs a successful diagnostic test on the evap system. That can take several hundred miles of driving. Does anyone know how if there's a way to force the diagnostic test? I don't know if it's possible, but I would assume that there has to be some way to clear this code on demand. I've been told that a regular ECU reset wont work, but I don't know for sure. It'd be worth a shot.

If it was my car, I would check for and fix any vacuum leaks, clean the MAF, put a new air filter in it, and try to reset the ECU. If that doesn't work, I'd find out what codes it still has. If the P0445 is the only one left, then I would drive it for about 500 miles and see if it resets itself. If that doesn't work, I'd put it on the diagnostics.

Sorry I can't be more help, but that's the best I can do for you. Good luck!

unseen

thanks for the help everyone! i knew yous would be knowledgable and be able to help. can anyone give me a lead on where to locate an 02 sensor at a reasonable cost? bank1 sensors are about 250, correct?

unseen

no one can direct me to a decently priced 02 sensor? ima have to go through toyota arent i? eeesssshh.

update: i cleaned up the hoses around the MAF, snipping cracked ends refastening them securely. it seemed to have cleared up some of the evap codes. the only codes that read now are too lean bank 1. hopefully the evap stuff remains gone.

unseen

ok so i thought i was starting to get ish cleared up. last time i scanned, there was only bank1 o2 sensor codes showing. i reset, and was going to install a new sensor i bought yesterday. however, in driving a few miles some new codes popped up. looks like it has increased in problems. anyone giving me a description of whats going on would help. im one step away from bringing it to toyota to have it fixed. i really dont want to, but im at my wits end on this.

codes:

P0138 - o2 sensor circuit high volts bank 1 sensor 2
P0441 - evap emission control system purge flow fault
P0445 - evap emission control system leak (large)
P0606 - PCM processor fault

please help if you can. otherwise im shelling out some cash to have this taken care of by the dealership. we know how thats going to end. thanks everyone.