Rough Idle - Fuel Injectors?

Hi all wise elders

Thank you for reading.

I lent my truck out and it was mistaken for a diesel.

2005 Taco 2.7 v4 2wd auto 215,000km

It was taken to a garage. The full tank of diesel has been drained, fuel system flushed, new autolight iridium tipped spark plugs and two new oem fuel injectors, 2 and 4 i believe as they were dumping gas - noticed on flushing the system.

The truck had power but was prone to dropping to low rpms and running very rough after a short runs when starting up for a second run.

Next came a check light, flashing then solid - code P0304 - cylinder 4 misfire.

I took it to Toyota and they swapped coil pack 4 to coil pack 1. The code was deleted and hasn't come back.
Also found a pending codes P0420 - something with the catalyc converter. And P433 something with air flow/pressure.

I'm now running a bottle of Toyota engine cleaner - put in the fuel tank.

The truck still idles rough.

My question is:
Where would make most sense to go from here to get the the bottom of issue?

Paul

 

To me, it would make sense that the cat converter could be damaged from such a mishap. Pumping what is essentially unburned oil through the cat could have caused it to clog and may have messed up the O2 sensors. Might want to start with O2 sensors and move to more expensive parts like the cat converter from there?

 

Maybe a good long run to heat everything up and maybe burn out any remaining residue out of the system. Hopefully you won't have to put a bunch more new parts in.

 

Even though this is on the air side of the system try cleaning or replacing MAF sensor for rough idle. As other member stated, try replacing O2 sensor. How was it the you were able to dispense diesel into a gasoline filler- always believed diesel spout was way too big to fit or come close to fitting? Gas can???

 

Thanks for replies

Misfire Code for cylinder 4 came back again after swapping coil pack 4 to 1

A sign that the coil pack is not the issue

Sounds like the fuel injectors or piston ring on cylinder 4 could be the issue

Any thoughts?

 

This really isn’t my area of expertise but I will ask if you have considered a leaking head gasket- loosing coolant or other signs? I likely missed it but when is the last time you replaced spark plugs or pulled plug to inspect it?

 

First step would be to kick the person in the nuts that put diesel in your truck. That’s common sense. And shouldn’t have happened even to the newest of drivers borrowing someone’s car. (Hopefully they are paying for all these repairs)

Then change the MAF sensor and look for leaks in the vacuum lines. The cats are probably clogged with oil now.

If you have bad rings on that cylinder, then ouch.