Hey guys,

So after I filled up tonight I added a bottle of the STP Fuel System Cleaner (can't get Techron in my area). I get about 1-2 miles down the road and my Check Engine Light comes on. I haven't checked the code yet.

Did the STP trip it? Did it knock something (debris?) loose in the engine? What gives?

My truck is a '99 V6 4runner (4x4) w/100k on it.

 

get the code first. don't speculate.

 

Could just be your time to clean the mass airflow sensor.
Especially if your running the amsoil oil charged filter
Mine goes on every 4-5 months or so.
Kenny S>

 

I would say you probably hit it on the head with the debris comment. My old explorer started running terrible after I put that stuff in. I changed the fuel filter and it ran much better. Pull the code.

 

I'll almost guarantee that you fouled out your older spark plugs! Trust me I did the same thing with techron, change your older plugs ( 30K max plugs) and you'll have no issues what so ever....
NOW HOW'S that for going out on a limb....?

 

how about a loose gas cap? that wil throw a code, have to make sure it clicks three or more times.

Just filled up, there is no way the cleaner made it through the whole system in 1-2 miles, and even then the cleaner is so diluted.