New to the car. 2002 GLE misfires/ catalyst code
 

Hey guys I’ve been reading some posts but I have not found anything specifically describing my issues. I may have 2 separate issues but I just bought this car so I don’t know the whole history. So the first things is when I start the car in the mornings, or anytime after it’s been sitting for a while, it runs like it has a misfire. It’ll idle fine but have a random “bump” and continue to idle. If I drive it right away and get into high rpms it will throw a misfire code to cylinder 6. I replaced the coil and it went away. It came back after a few weeks and the same cylinder. I swapped the new coil to cylinder 4 and the misfire went to cylinder 4. It’s a cheap duralast coil so that may the issue but I’m not sure. Im
thinking of getting a new coil and some new plugs for all the cylinders. The misfire seems to go away after the car is warm but will sometimes do it under heavy acceleration like going on the freeway. My other issue is I get the P0430 code as well. I’m not sure if that code will also contribute to misfires or running lean. Any advice ? As far as I know the o2 sensors have not been changed. Also it has 123509 miles so that seems low to me for a new catalytic converter

Stay away from cheap coils. Our cars like Hitachi coils and that's what you should do. You can get them here: https://www.rockauto.com/en/catalog/...tion+coil,7060 , and the price is reasonable.

Re. the P0430 it's a common problem on these cars. The root problem is either the Cat itself or the monitoring sensor. I would start by replacing the sensor first. (There are other solution but not for us in California or NY ..... just search).

thank you I’ll definitely be ordering that coil for sure. I figured I’d also clean the MAF sensor and do the plugs anyway. As for the p0430 code you said to replace the sensor. The code says bank 2 so does that mean replace a sensor for the rear bank? Like a 02 sensor? I think they’re are quite a few 02 sensors

Pre-cat sensors provide data for mixture, post-cat sensors only monitor cat function. It's nothing.

You’re right, 120k is very low for a bad CAT. Look for underlying prob. 5th gen VQ 3.5s are oil burners. Carbon buildup may be fouling your cats. Lots of posts about it.

I agree about the hitachi coil.

For the o2 code, look at the sensor wiring for damage/shorting out. My guess is that it is rubbing on some part. Worst case, replace the sensor first.

Hey thanks to everyone for giving me advice. I ordered the Hitachi coil. But right now I also found this. I’m not sure what this part is called but I it looks to run with the intake manifold, not sure if this can be a contributing issue
https://cimg4.ibsrv.net/gimg/maxima....05be6add68.jpg

that is the VIAS solenoid, it controls the variable intake system. which means right now you top end power is being choked down a bit. most people on here just delete it.

https://cimg5.ibsrv.net/gimg/maxima....48f3088919.jpg

I agree w/Uptown, did mine a few years ago. Simplest mod in the world and idle is solid and smooth.

Hey everyone I got an update. When the car was misfiring it also started to throw a p0335 code. I do all got that Hitachi coil in it and it runs great. Also that p0335 code is gone I have no idea why. I also just replaced the intake sensor, did not do the delete but the cars running great again thanks for the input peoples. All I have left is the 02 sensor code