Help. Smell of fuel coming from exhaust

[wildgoose]

Not to revive a dead thread but I was googling this issue a few months ago after my girlfriend noticed the heavy smell of raw fuel on a cold start, I brushed it off but i started noticing it more and more and wasn't really seeing any conclusive fixes in the threads I was reading. 2020 with 70k, replaced the plugs a few months ago for good measure & i regularly run techron through the fuel system but i wouldn't have been surprised to find leaking injector causing this.

A week or 2 ago I replaced the maf sensor after diagnosing some performance issues for a few months and it came with a massive performance boost it feels like a new truck again + the raw fuel smell on cold start is completely gone now, just a slightly sweet smell.

Wanted to leave a comment with a definitive fix for anyone else who might be experiencing this.

 

[Devbot]

Not to revive a dead thread but I was googling this issue a few months ago after my girlfriend noticed the heavy smell of raw fuel on a cold start, I brushed it off but i started noticing it more and more and wasn't really seeing any conclusive fixes in the threads I was reading. 2020 with 70k, replaced the plugs a few months ago for good measure & i regularly run techron through the fuel system but i wouldn't have been surprised to find leaking injector causing this.

A week or 2 ago I replaced the maf sensor after diagnosing some performance issues for a few months and it came with a massive performance boost it feels like a new truck again + the raw fuel smell on cold start is completely gone now, just a slightly sweet smell.

Wanted to leave a comment with a definitive fix for anyone else who might be experiencing this.

Thanks for the input, but you're in the 3rd gen section FYI.

 

[gamefreakgc]

Not to revive a dead thread but I was googling this issue a few months ago after my girlfriend noticed the heavy smell of raw fuel on a cold start, I brushed it off but i started noticing it more and more and wasn't really seeing any conclusive fixes in the threads I was reading. 2020 with 70k, replaced the plugs a few months ago for good measure & i regularly run techron through the fuel system but i wouldn't have been surprised to find leaking injector causing this.

A week or 2 ago I replaced the maf sensor after diagnosing some performance issues for a few months and it came with a massive performance boost it feels like a new truck again + the raw fuel smell on cold start is completely gone now, just a slightly sweet smell.

Wanted to leave a comment with a definitive fix for anyone else who might be experiencing this.

Sometimes instead of a full replacement, one can very gently clean the MAF sensor with MAF/carb cleaner to remove dirt and deposits to get the same result. I don't know the design of the 5th Gen 4Runner's MAFs so it may not be a simple but it has held true for every other generation of 4Runners.

 

[wildgoose]

Thanks for the input, but you're in the 3rd gen section FYI.

Ah didn't see that, still relevant tho

 

[wildgoose]

Sometimes instead of a full replacement, one can very gently clean the MAF sensor with MAF/carb cleaner to remove dirt and deposits to get the same result. I don't know the design of the 5th Gen 4Runner's MAFs so it may not be a simple but it has held true for every other generation of 4Runners.

Oh for sure I cleaned the sensor twice before replacing it, first clean completely fixed the issue but the second time it did almost nothing which just reaffirmed my thought that the maf was close to dying. Honestly i think the carbon filter in the air box was full of dirt and kept contaminating the sensor i cut it out so we will see if it gets contaminated again i drive from one dirt road to another so if the sensor gets contaminated again i will likely install a snorkel.