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I have been getting a P0171 (bank 1 cylinder 1 too lean) code after I replaced the spark plugs. I googled the possible causes and what I found was that it could be a malfunctioning PCV valve, O2 sensor, or loose hoses. I checked all of the hoses and replaced the PCV valve with a new one.
Disconnected the battery for a solid 15 minutes and reconnected. The CEL would come on again but would disappear after a few days of driving.
Some other symptoms I have noticed is that as I come to a complete stop, the engine RPM would suddenly shoot up from around 700 RPM to around 1200 RPM and then fall back down to 700 again. Sometimes when I am idling in traffic the idle would drop to around 300 RPM and the engine would vibrate a little, as if it is about to stall.
Need some input on what could be causing these issues!
Well this happened after changing spark plugs, so why think its something else? Check your plugs and inspect for damage or improper gaps. Luckily its bank one, so its the easier front 3 plugs. Also check components you removed in case you may have accidentally damaged them while removing/reinstalling them, specifically around the pcv.
Last edited by Mr Jokster; Mar 14, 2016 at 10:32 PM.
Well this happened after changing spark plugs, so why think its something else? Check your plugs and inspect for damage or improper gaps. Luckily its bank one, so its the easier front 3 plugs. Also check components you removed in case you may have accidentally damaged them while removing/reinstalling them, specifically around the pcv.
Thanks. I will give it a check!
It cannot be the gap, unless the spark plug was somehow damaged. I bought iridium plugs so no gapping required!
Dont know where you got that idea, plugs have to be gap regardless. Being that they're iridium doesnt mean they dont need gapping, sure they come pregapped, but doesnt mean they cant bend during shipping. Either way, always need to check gap before installing