Hesitation while accelerating, mild gas smell, P0301 and p0171

[DWilliam]

I’ve had this issue for almost a year now. CEL is p0171, p0300, p0301. I replaced all plugs and wires, and coil on bank with cylinder 1. I have a mild fuel smell not only when pumping gas but after driving as well which I attribute to the system lean code. Also, I have a slight hesitation when I accelerate and almost feel like I’m underpowered if that makes sense. The hesitation is much worse after I fill up the gas tank.

I was hoping to do the injectors, but then my head gasket blew so obviously that came first. Now I’m ready to hopefully get rid of the codes and get the Motorwest set. Do these symptoms sound like injectors? Last year I had Evap codes and replaced the overflow check valve, and did a new fuel pump and filter while the tank was dropped.

If the consensus is injectors, other than the crush washers, what gaskets do I need to replace?

 

[jgue467]

The 0171 is most likely a leak in air intake - when mine had that code it needed a new intake hose - see pic. That code alone will make it run poorly and use lots more gas as the ECU is trying to make up for the extra air from the leak by adding all the fuel it can and it is still not enough - hence the 0171m- too much air.

I would fix one thing at a time - not sure why you still have miss codes - may need to do a Live stream analysis for that. Luck and enjoy the Runner.

 

[DWilliam]

The 0171 is most likely a leak in air intake - when mine had that code it needed a new intake hose - see pic. That code alone will make it run poorly and use lots more gas as the ECU is trying to make up for the extra air from the leak by adding all the fuel it can and it is still not enough - hence the 0171m- too much air.

I would fix one thing at a time - not sure why you still have miss codes - may need to do a Live stream analysis for that. Luck and enjoy the Runner.

Thank you. Forgot to mention that I already replaced that, and checked for air leaks with carb cleaner and didn’t find anything. I also cleaned the MAF sensor and TB. Also replaced the spark plugs, wires, and coil on cylinder 1. Still have the same codes.

 

[DWilliam]

Any other ideas, or does it seem like a bad injector?

 

[phattyduck]

Any other ideas, or does it seem like a bad injector?

If the injectors haven't changed, yes - there are plenty of examples of bad injectors at this age. The Motorwest "upgraded" (stock flow) injectors should be a good swap.

What source/brand did you use for the ignition components?

If you had on injector partially working that could have led to your head gasket issue (if it was on the same or adjacent cylinder). 5 cylinder rich, 1 cylinder lean = lots of bad stuff.

-Charlie

 

[DWilliam]

If the injectors haven't changed, yes - there are plenty of examples of bad injectors at this age. The Motorwest "upgraded" (stock flow) injectors should be a good swap.

What source/brand did you use for the ignition components?

If you had on injector partially working that could have led to your head gasket issue (if it was on the same or adjacent cylinder). 5 cylinder rich, 1 cylinder lean = lots of bad stuff.

-Charlie

Thanks Charlie. I used NGK stuff for the ignition replacements. I had no idea the lean codes and possible bad injector could’ve led to the head gasket failure. I guess I need to expedite my order and repair so it doesn’t happen again.

 

[phattyduck]

Thanks Charlie. I used NGK stuff for the ignition replacements. I had no idea the lean codes and possible bad injector could’ve led to the head gasket failure. I guess I need to expedite my order and repair so it doesn’t happen again.

Where did you buy those NGK parts from?

-Charlie

 

[DWilliam]

Where did you buy those NGK parts from?

-Charlie

It’s been a few months but I’m pretty sure they all came from rock auto. I found a local shop that will do the injectors, so I’m going to do the plugs and the rest of the coils as well just to be safe.