2005 RL. 117k miles. Filled up a few days ago, currently have a quarter tank. Before I filled up I put some Lucas engine treatment in. Noticed some sputtering at idle, no codes until last night when I opened it up a little bit. Blinking CEL.

Now it says code P0305 which is a misfire in cylinder 5? Car has 117k miles on it and Im guessing the original plugs. Acura wanted $110 to diagnose. Should I just go ahead and replace the plugs myself? I'm a little tentative to attempt on my own.

Anyone else with similar experience? Advice is appreciated. Thank you

 

https://acurazine.com/forums/2g-rl-2005-2012-76/easy-replace-spark-plugs-looks-846245/

This thread starts off innocently enough and would appear to have a happy ending... until you get to post 29.


The fill-up/engine treatment seem a little too suspicious. I would run the tank down and refill with good gas before moving forward.

 

I wish I never read post 29. I have an appointment for tuesday, maybe I'll just be gentle with it until then and get my proper diagnosis

 

Was that the only code ? no P0300 ? I would start with swaping the coil from cyl 5 w/ any of your other coils and see if the mis fire follows that coil, if it does that coil is your problem. And a new set of plugs couldn't hurt if they are the originals. also if you pull a plug and see a red discoloration on it that is the result of fuel additives.

 

Swapping the coil pack around is the best method by far as well as the cheapest on the pocket. My rl would give it to me on start up seems like just when it was cold outside. I could go days with out the on board computer detecting it. I swapped the coil pack and the same cylinder miss fired. I was going to give it an overhead and hope to find a valve out of adjustment but while doing a leak down test i saw a small trail of coolant. It was the worse case a small hair line crack in the head. Strage thing I never smelt antifeeze and the car still had plenty of power.

 

I would run a few tanks of premium to flush out that Lucas before you throw money at it.

 

UPDATE: changed the plugs. They were not the original. However, the plug in cylinder 5 was extremely loose and beat. The others looked good. Tightened down plug 5, no codes, runs great and that light tick I heard previously is completely gone.

great success!

 

Nice!

Definitely should check the plugs on occasion.