Join Date: Jan 2012
Location: Orangeville, PA
Feedback: 0 reviews
I need to see if anybody can help with an engine miss I've been having. It's like a slight stumble every 4-5 seconds. It's only ever thrown a check engine light twice and it was the one for "misfire cylinder #3" (can't remember the code right now but it was the same both times). The code went away on it's own after a day or so.
I changed the plugs and plug wires about a year ago (~15k miles). I used the OEM plugs and a set of advance auto wires. I figured it was the cheap wires so I just put on a set of AC delcos and it's still there. The plugs look like new still so I haven't bothered with them. The EGR valve was replaced about a year and half ago due to it going bad and throwing a CEL. I've replaced the PCV valve (even though it was only a year and a half old too) and installed a new air filter. I've removed and cleaned the throttle body along with spraying carb cleaner along the vacuum lines to see if one was leaking. It's not using any coolant, blowing white smoke and no coolant in the oil so I'm pretty sure it's not a head gasket.
Can anybody please help me in figuring out what it could be because I'm at a dead end here. Could the ignition box be bad but not completely fail, just miss every now and then?? Oh and it's an 07 JK 3.8 automatic tranny with 103,000 miles on it. I've always performed the maintenance on it since I got it at 50,000 miles.
Also wanted to add that my gas mileage (13.5-15mpg) is the same and it seems to run fine under throttle and has the same (lack of) power it's always had since I put 35's on it. LOL So I doubt it's a clogged cat. It also has no exhaust leaks that I can hear (I've replaced the drivers side manifold twice now).
I'd greatly appreciate any help. Thank you.
Mine: 07 Unlimited Rubicon. Red rock crystal. RC 2.5" spacer lift. 35x12.50 mtr/k's mounted on 15x8" black mb72 wheels. Riddler diffs covers, PSC evap skid. Sleeved, gusseted and skidded front axle.
Hers: 05 WK limited 4.7, Midnight blue pearlcoat.