What have you done to your Tacoma today? 1st Gen Edition

Must be common because mine has a small rust hole on that side and it's never had a plastic liner in it

 

Looking good for Sunday chores.

 

Okay guys this code is starting to piss me off now. P0171 "System Too Lean - Bank 1" it only happens on hard acceleration such as when entering a freeway or when going up a steep grade. I have a K&N CAI on - I suspected it was a dirty MAF so I pulled it off to clean - but the damn thing was perfectly clean. I have no idea what is is anymore - O2 sensors maybe?

 

Usually 02 sensor bank one is before cat

 

Kind of a weekend of work but here goes.

Cleaned headlights and I finally feel safe to drive at night again. Also, added new side marker light housings. Also replaced all bulbs since some were out.



Spray on bedliner on the front grille...No reason in particular other than I was bored.


Bolted down my Allpro bed rack and got rid of the vise grip temp holders.


Ripped out the antenna mast completely and clipped the antenna wire because I just got frustrated with it. Now I get to pull the radio and re-run the entire deal :-/

 

Went for a little cruise cause I'm bored.

 

Had oriellys do it. Didn't tell me the codes

Went back by and got a pic

 

I would change the sensor. My bank 1 was an AFR sensor, but my truck is a California truck so yours could just be an O2. I replaced mine after it was throwing bank 1 low voltage codes and my mpg's took a noticeable hit. I had about 165K on the factory sensor so I figured it was time anyway. I got a Denso for like $60 shipped on Amazon

 

I always thought it was my cold air intake - I'll try replacing the O2 sensor.

 

EDIT* Just saw you're a 2.7l, I would assume the diagnostics would still be the same, but I aint no rocket surgeon

Copy and pasted this from a 4runner site, pretty good steps if you have a way to monitor fuel trim or O2 sensor voltage


1999 Toyota 4Runner 3.4L, Eng Cfg V6, Eng Des 5VZFE, USA/Canada

Hotline Archive
With OEM Direct diagrams, components, TSBs, and R&R procedures

Number: 482996
Vehicle Application:
1998 4Runner 3.4 1999 Tacoma 3.4
1999 4Runner 3.4 2000 Tacoma 3.4
2000 4Runner 3.4 2000 Tundra 3.4

Customer Concern:
Has a check engine light on and a code P0171.

Tests/Procedures:
1. Monitor the fuel trim readings at idle and at 55 MPH driving down the road. If the numbers are low at idle but climb on a part throttle cruise, the airflow meter could be reading low or it may also have low fuel pressure. The mass air flow sensor grams per second should be 3.3-4.7 at idle and 12.9-18.3 at 2500 RPMs no load, if the readings are low the sensor could be bad.

2. Monitor the calculated load reading on a wide-open throttle acceleration. The reading should go to 85% or more. If not, then the airflow meter could be faulty.

3. Monitor the oxygen sensor inputs, both front and rear oxygen sensor signals. The oxygen sensor should not stay high or low voltage for extended periods of time. If the oxygen sensor shows low voltage and the fuel trim readings climb, check the performance of the oxygen sensor.

4. Check the vehicle for a vacuum leak by spraying carburetor spray around the intake manifold while watching the fuel trim readings. If the readings change, there is a vacuum leak.
Tech Tips:
If fuel trim readings are high at idle and go down on a free rev, there is a vacuum leak. If the fuel trim readings are high at idle and at cruise, suspect fuel injectors.


Diagnostic Codes
P0171

Confirmed Fix
225 - Mass Air Flow (MAF) Sensor
9 - Engine Air Filter, Mass Air Flow (MAF) Sensor
4 - Oxygen (O2) Sensor(s)
2 - Fuel Pump
2 - Heated Oxygen Sensor (HO2S) Bank 1 Sensor 2 (B1S2)
2 - Heated Oxygen Sensor (HO2S) Bank 1 Sensor 1 (B1S1)
1 - Front Oxygen (O2) Sensor
1 - Vacuum Leak
1 - Fuel Injector(s), Mass Air Flow (MAF) Sensor
1 - Cruise Control Vacuum Line
1 - Intake Manifold, Mass Air Flow (MAF) Sensor
1 - Mass Air Flow (MAF) Sensor, Throttle Body Cleaning Procedure
1 - Mass Air Flow (MAF) Sensor, Mass Air Flow (MAF) Sensor O-Ring
1 - Exhaust Pipe, Mass Air Flow (MAF) Sensor
1 - Air Intake Tube
1 - Mass Air Flow (MAF) Sensor, Throttle Body
1 - Air Fuel Ratio (AFR) Sensor
1 - Engine Vacuum
1 - Oxygen (O2) Sensor, Bank 1 Sensor 2

 

So that means mines done? Woohoo

 

Does anyone know where the abs solenoid relay is?

 

1/4"? I was considering doing behind the rocks, but not Pritchett. Gotta get the truck back home to the east coast. Cliffhanger is a priority for me though.

 

Pretty good steps for diagnosing. If it is setting under heavy acceleration only, I would suspect the fuel can't keep up and it is going lean. A dirty MAF can also cause this as it lets more air past than it is measuring which also causes a lean condition

 

Installed a backup camera mirror with auto dim, compass, and temperature. The camera I got was crap so I'm currently waiting on another one.

 

It only ever happens during heavy acceleration. If I'm just cruising down the street to get groceries it never turns on.

 

New grill and light housings

 

Out if curiosity, you ever change the fuel filter? I just changed the factory one with about 170k on it. Haven’t cut into it yet but I bet it’s pretty damn gross

 

You know what I don't think it's been changed yet. The truck only has about 90,000 miles so I think it's due time. I checked the Toyota service history and it never said anything about the fuel filter. I did notice the truck had the same P0171 code back in 2010 and it was solved by cleaning the air intake? Something like that