Decided to try direct application of sea foam engine treatment thru the upstream O2 ports.
I poured a bottle in each port, allowed it to sit. Smoked heavily for ~40 miles. I week after treatment no return of faults.
Note:I had to deal with a cross threaded 02 sensor port from the previous owner. Chasing the threads wasn't an option. I drilled and tapped an oversized port and installed an insert, all available on Amazon. I removed the cat head shield and upper radiator hose to get room to work.
18.5 MM drill
20 x 1.5 MM tap - I used Alpha tools HSMTT271044, it had good lead in to help center the tap.
TIME-SERT Drain Pan Insert M18x1.5X10MM Part # 18151
I poured a bottle in each port, allowed it to sit. Smoked heavily for ~40 miles. I week after treatment no return of faults.
Note:I had to deal with a cross threaded 02 sensor port from the previous owner. Chasing the threads wasn't an option. I drilled and tapped an oversized port and installed an insert, all available on Amazon. I removed the cat head shield and upper radiator hose to get room to work.
18.5 MM drill
20 x 1.5 MM tap - I used Alpha tools HSMTT271044, it had good lead in to help center the tap.
TIME-SERT Drain Pan Insert M18x1.5X10MM Part # 18151