revisiting truck stalling and have codes

[silver4est]

few weeks ago my 01 started stalling at stop signs and would idle rough but drive fine, it got bad enough that it would stall seconds after starting it. I was busy so it sat a few days, then I disconnected battery and cleaned the throttle body. it had very little black gunk around the throttle plate. I also found the hose running back to the airbox torn badly and cut the end off it and reinstalled. also the plug wire cap at cylinder one was not seated properly and showed signs of arcing, I reconnected it to the coil pack. hooked battery back up and started the car, it died within a couple seconds. the lug wire was disconnected again. reconnected it again and truck fired right up and runs/idles fine. 10 miles later I got CEL, the next day the light turned off and has not come back but I am still getting crap gas mileage, like 120 for half a tank with very conservative driving, its been bad for 3 months now.
finally checked codes, I got P0171 system too lean (A/F lean malfunction, bank 1)

my findings say either a vacuum leak or dirty or faulty maf. I have a new pcv valve coming and am gonna swap out vac lines and clean mad in hopes of curing this problem.

I noticed that the black box/silencer on the intake hose rests against the number one coil pack, wonder if that knocked the plug wire out by vibration? sounds like a long shot I know.

so I think I am on the right track there right now but also have another 2 codes

C1223 malfunction in ABS system
C1246 malfunction in master cylinder pressure sensor

the first code I believe is set because of the second code from my research.
master cylinders are crazy money.

car behavior:

traction control is very sensitive, driving up a small incline from stop or pulling my 400 pound hobie cat on trailer will trigger the noisy traction control or vsc very briefly, even on not slippery surface, tires are 265-75-16 new duratracs

Brake pedal is a little soft, just enough to notice but it does not go to the floor or anything, feels like there could be some air in the lines, brakes are still grabby.

I do not have any lights on the dash, they flash when I first start the truck but thats it.
everything I find online people have vsc and trac lights lit up, I don't.

Could air in the system cause the malfunction code? or does it appear I need to replace the master cylinder? Could this all be triggered by a vacuum leak I might have?

I can answer any questions to help diagnose this.

thanks guys, I don't yet want to torch my car like the guy who hates spiders

Forrest

 

[jgue467]

When you cleaned the intake did you get to the IAC also?

Have ya run any fuel/injector treatment in gas tank like say seafoam or startron? :cowboy:

 

[silver4est]

Have not run anything in the gas no, those make me nervous. I have the 01 which does not have access to the IAC, there are no openings in the throttle body.

I could try an injector cleaner or seafoam,

 

[jgue467]

Don't sweat seafoam, mechanics use it on intakes to decarbon.

I run startron, its enzyme based, read here: Star Tron Enzyme Fuel Treatment

I use it on all my engines, makes smaller engines fire right up. Its a slow and gentle cleanser, alcohol fuel treatment/stabilizer (for smaller/older engines). It might help, about $8 at walmarts marine section (not auto). Luck and enjoy the runner. :cowboy:

 

[silver4est]

I'll read that link, just add it to a tank of gas?

 

[silver4est]

Kinda regret buying a car without a full history and maintanence report, I was thinking it's a Toyota no worries, woops.

 

[stir_fry_boy]

few weeks ago my 01 started stalling at stop signs and would idle rough but drive fine, it got bad enough that it would stall seconds after starting it. I was busy so it sat a few days, then I disconnected battery and cleaned the throttle body. it had very little black gunk around the throttle plate. I also found the hose running back to the airbox torn badly and cut the end off it and reinstalled. also the plug wire cap at cylinder one was not seated properly and showed signs of arcing, I reconnected it to the coil pack. hooked battery back up and started the car, it died within a couple seconds. the lug wire was disconnected again. reconnected it again and truck fired right up and runs/idles fine. 10 miles later I got CEL, the next day the light turned off and has not come back but I am still getting crap gas mileage, like 120 for half a tank with very conservative driving, its been bad for 3 months now.
finally checked codes, I got P0171 system too lean (A/F lean malfunction, bank 1)

my findings say either a vacuum leak or dirty or faulty maf. I have a new pcv valve coming and am gonna swap out vac lines and clean mad in hopes of curing this problem.

I noticed that the black box/silencer on the intake hose rests against the number one coil pack, wonder if that knocked the plug wire out by vibration? sounds like a long shot I know.

so I think I am on the right track there right now but also have another 2 codes

C1223 malfunction in ABS system
C1246 malfunction in master cylinder pressure sensor

the first code I believe is set because of the second code from my research.
master cylinders are crazy money.

car behavior:

traction control is very sensitive, driving up a small incline from stop or pulling my 400 pound hobie cat on trailer will trigger the noisy traction control or vsc very briefly, even on not slippery surface, tires are 265-75-16 new duratracs

Brake pedal is a little soft, just enough to notice but it does not go to the floor or anything, feels like there could be some air in the lines, brakes are still grabby.

I do not have any lights on the dash, they flash when I first start the truck but thats it.
everything I find online people have vsc and trac lights lit up, I don't.

Could air in the system cause the malfunction code? or does it appear I need to replace the master cylinder? Could this all be triggered by a vacuum leak I might have?

I can answer any questions to help diagnose this.

thanks guys, I don't yet want to torch my car like the guy who hates spiders

Forrest

The ABS codes have nothing to do with your P0171 code. Fixes for P0171. First clean your MAF with MAF/brake cleaner.

The P0171 code could be caused by a vacuum leak, but the most common cause is by far and away the MAF (usually dirty).

The ABS/TRAC systems are expensive on the 01-02 4Runners. Maybe someone else with more experience can suggest a fix? Maybe a zero point calibration?

Wouldn't hurt to flush the brake system with clean, previously unopened Toyota Brake Fluid (DOT 3). I only use Toyota fluid because it's such an expensive system and I want to minimize issues.

Have not run anything in the gas no, those make me nervous. I have the 01 which does not have access to the IAC, there are no openings in the throttle body.

I could try an injector cleaner or seafoam,

That's correct, there is minimal access to IAC. It's electronic drive-by-wire throttle input.

Injector cleaner is a good idea, wouldn't hurt. But I suspect that the cause of the P0171 code is either the MAF, a vacuum leak, or very rarely an O2 sensor.

Definitely would recommend spark plugs (NGK or Denso dual grounded), and plug wires with coil pack boots (OEM on wires, NGK for boots as the coil pack boots only come with the coil packs from the dealer).

 

[silver4est]

Check
Will swap plugs
Wires are pretty fresh blue NGK wires
Swap vacuum lines
Clean maf

Brake fluid flush and bleed

Didn't expect the abs cod s related to the lean code, had to reach

I'd rather not throw money without knowing what will happen, but I'm under influence that taking it to a shop will net a 1000 plus dollar bill

 

[stir_fry_boy]

Also coil pack boots

 

[silver4est]

Roger, ngk boots, I'll check mine first but put them on list. I remember from my Audi 5cyl 20v turbo plays that degrading boots would cause havoc on running conditions however those where under 26 pounds of boost, none the less learn to check all things ignition.
Thanks!!
I'll report back after

Big concern is the abs problem

 

[stir_fry_boy]

Roger, ngk boots, I'll check mine first but put them on list. I remember from my Audi 5cyl 20v turbo plays that degrading boots would cause havoc on running conditions however those where under 26 pounds of boost, none the less learn to check all things ignition.
Thanks!!
I'll report back after

Big concern is the abs problem

If you don't have any maintenance history, I'd be much more concerned about a lot of other things besides the ABS. The ABS system in no way affects your ability to brake (although ABS has shown to stop the truck quicker in adverse weather) Things I'd look in to:
Ball joints
Bushings
Timing belt

Just to name a few