P0171 and traction control light

Looking for some wisdom please. My CEL and traction control light have been coming on together for a couple of days now. The code is P0171 and the trac light stays on solid. It already has a new fuel pump installed. Under a big load it will buck a bit til I back off the throttle. It's the trac light that has me wondering. Hopefully someone has experienced a similiar event? TIA Cheers, Dave

 

For certain check engine lights the trac like will also come on. That code has a wide variety of things that could cause it. Did this start happening after the new fuel pump was installed?

 

Yes, after the new pump. I misdiagnosed the the original fuel pump as faulty when the chip key was intermittently not signalling the immobilizer to run the pump. Took the box off to replace, so pretty sure I didn't kink any hoses on the install. I seafoamed it in this time frame too. A whole can in a full tank of fuel. I'm going to test the fuel pressure tomorrow. Maybe the seafoam knocked something loose and is now in the fuel pressure regulator? It actually runs ok now, so I have some time to diagnose. I ASS U ME that the new pump is not part of the equation, but have had experiences where using new parts as troubleshooting tools has not worked out well ;-)

 

Here have you, I'd start with reading the voltage values on the A/F sensor, bank 1 is passenger side.

 

If the problem started after the new fuel pump went in.. I'd be looking at fuel pressure and volume

 

why just 1 bank then, would the pump affect both sides the same or maybe I’m misdiagnosing

 

Bank 2 may code eventually, maybe bank 1 was just the first side to recognize the problem.

 

It's a 2.7 liter 4 cylinder. Does that make a difference? Cheers, Dave

 

Nope, you still have a lean code

 

Haha, no, I meant the bank 1 and bank 2 thing!

 

well now that you mention that, i'd say hook up a gauge to your fuel line and check the idle and pressure at WOT. Could be the pump or the resistor.

 

Yes, there's only one bank on a 4 cylinder, so it could be fuel, maf, vacuum leak and its harder to find.

 

How long has it been since the MAF sensor was cleaned with the proper product -> CRC

 

About 2 days!

 

how did you clear the code?

 

Don't know if seafoam always plays well with o2 sensors. May need to check that and then do a routine tune up.

 

The 2.7 Liter 4 cylinder has no fuel pump resistor.
You also want to check the fuel pressure with a tee fitting off the main fuel line. do not dead head as you will get an incorrect High Pressure. The regulator is on the fuel rail.

 

OBD2 reader. Cleared it and was back again after a couple drives. Leaning towards fuel pressure, gonna test it today

 

I've never heard anything about adverse effects on 02 sensors. It's pretty widely used as a 'tuneup in a can'

 

I'm setting up for a fuel pump test. Would my FLAPS have the adapter for the Toyota fittings?