So, I had been idling rough for a while and been making repairs accordingly. I change air filter regularly (yes I did run a K&N for about 16000 miles until reading post against use and terminated use about 8000 miles ago, hopefuly MAF is not shot but certainly a possibility). I flush the engine periodicaly. Recently replaced Iridium plugs with Bosch +4 and installed a set of Magnecore wires attempting to erradicate a cyl.#5 misfire. Shortly after I performed a Seafoam treatment on the induction system. Now 1500 miles later scanned the codes and to my surprize had 12 faults. Some were dublicates indicateing misfires on cyl. #5, #6, & #7, also had P1300-random misfire, had P1590-rough road fault, P0171 and 2 codes which indicated I need to replace my O2 Sensor (which I had already known and am currently scheduling the time to replace).

Question: would the Seafoam treatment temporarily cause multiple fault and misfires???

Any other suggestion direction on approach would be helpful.

138000 mi.

Thanks

 

Go clear the codes and recheck. Yes I have seen a couple of times where Seafoam will throw a misfire, especially on a heavily carboned engine.
So, go clear them, see what pops up then get back to us.