2003 V8 Sport 4x4 just threw three codes- plan of attack

[brett_murphy]

My wife took the T4R out for an errand, and it started running like crap just down the street- rough idle, down on power, CEL on and "VSC TRAC" "VSC OFF" also came on. This was *abrupt*- it was running like a top just a week ago, but them temperatures have been weird the past week: from the 70s down to the 20s, back and forth.

I limped it back home, and got the following codes using an OBDII reader:

P0300 - Random Misfire
P0171 - System too Lean bank 1
P0175 - System too rich bank 2

The "VSC TRAC" "VSC OFF" lamps went off when I turned it off and restarted it.

Given that it was so sudden, I am thinking a connector or sensor went bad. The plan is to clean the MAF and check the plugs/wires/coils and lastly, the 02 sensors and all of their connections on the wiring harness.

Any other thoughts?

 

[mizak82]

Random misfire you would think are cylinder 1 or 2 based on the three codes.. Tough to tell with that code.. but with the other two I'd guess would be fuel pump. Or faulty injectors. Or maybe a fuel filter. Shitty winter gas.

The lean one is the main concern.

But I'd try premium gas. And an fuel injector cleaner the next tank for sure.



Sent from my iPhone using Tapatalk

 

[brett_murphy]

I changed the plugs and it improved enough to make it seem like a cylinder isn't firing properly at all. That should say how bad it was running before. There was a very strong scent of gas in the exhaust, too.

I'm leaning towards a coil or a fuel injector. It's getting late, I'll mess with it more over the weekend or something.

Looks like the Forester is getting tagged in for going to the in-laws house, though.

 

[brett_murphy]

Well, that got easier. Last night I cleared the codes, disconnected the battery, let it sit for a bit and hooked the battery back up. I just went out and started it up again and let it run for a few minutes.

Misfires on cylinders 1, 2, 3, 4, 7 and 8. I seriously doubt that both 02 sensors failed or that 6 injectors or coils failed. I'm now leaning towards a fuel pump or fuel pressure regulator or something like that.

Of course, I have to drop the fuel tank to even test the fuel pump, and it's dang near full.

 

[mizak82]

Can you get to the fuel pump from the inside under the seat?


Sent from my iPhone using Tapatalk

 

[Oneluv13T4R]

Can you get to the fuel pump from the inside under the seat?


Sent from my iPhone using Tapatalk

No you can not..the only thing that access panel is used for is to disconnect the lines and a sensor to be able to drop the gas tank to be able to pull out the fuel pump. I have an 2003 V6 and just changed mine out last week from having a similar issue but my codes were 420 bank 1 430 bank 2 and I think code 175 sensors stuck on lean for both banks 1 and 2 basically popped 4 codes for all 4 o2 sensors ...and putting a new OEM complete fuel pump canister didn't do a damn thing to help that issue ...

 

[brett_murphy]

As a side note, the tensioner, which was from Gates and only a few months old, went bad. Luckily, it didn't get that far out of whack. I replaced the tensioner with a Toyota part, reset the timing and have not had a problem since.

 

[46runner]

As a side note, the tensioner, which was from Gates and only a few months old, went bad. Luckily, it didn't get that far out of whack. I replaced the tensioner with a Toyota part, reset the timing and have not had a problem since.

following this thread. riveting. keep the updates coming