Hi y'all,

I got an 04 a few weeks ago and I've been tweaking things progressively to get it in good shape. I've been looking for help on a few things so I figured Id make a thread on everything I find and troubleshoot so maybe people don't have to search around so much.

Current issues:
-steering wheel vibration around 60-65 mph
-sometimes slow engine start
-engine shudders on turning off and occasionally at idle

Fixed issues:
-spark plugs
-low idle
-rear driver side door light not working

Modifications:
-Kenwood Radio
-LED lights
-Group 27F battery

So far, I dont think I will be doing anything crazy but I figured I would start with some info on this stuff since I didnt find much while looking.

I got a kenwood DMX706S unit with car play and bluetooth. The biggest thing I had to figure out was the wiring. Turned out they had a harness that matched the plugs in the car and the colors of the kenwood harness and the place I got the radio from. They also had little wings that bolted on to match the interior of the car. The radio brackets from the car screw onto the new radio. you may need longer screws for the side plates. I will try to remember to update the brands later but the shop was Safe and Sound in Anchorage, AK and you could get the brands from them.

Just know that the colors of the wiring are not what you think they are. The wiring diagram is available on this forum on one of the main pages and I was able to confirm it on there that the harness was right even though it looked wrong. for the USB connection, I ran that under the center console and into one of the open plates next to the arm rest. It didn't quite fit but with a .5m apple cable, it is perfect. I did the same with the microphone wire and hung that on the side of the center console.

For the lighting, the low beams and fogs are 9006s, the high beams are 9005s. I used Nilight leds for the low and high beams. they are super bright and have a 2 year warranty. I've used their pods before to great effect on my GX. For the Fogs, I used Lasfit since they had an option that switched colors from white to yellow (and I had a code ARC10 for 10% off). One of these actually had a defect and they responded to my Instagram post saying they would send me a new one. I also added Lasfit 194/168/T10 or whatever they are to the doors (one in each door). That to me is one of the best lighting mods you can do that no one does and its super easy/cheap. All you do is use a trim tool to pop the housing out from the side opposite the hinges. then its pretty self explanatory.

For the battery, I had my old GX battery sitting around so I threw it in there. the tray in my V6 was already the size for the 27F battery. 60 or so more CCA but its something.

After getting fluids done, I replaced all the spark plugs with the Denso pre-gapped iridium spark plugs. I noticed a ticking noise coming from one side so I took them all out, looked at them (one looked too clean) and switched the coil pack on that one. Still got a tick so I put an old one in and the tick went away. took the plug back and got a replacement one and it works. Random denso plug dead from the factory.

After reconnecting the battery, the car was idling low and when I put it in reverse, it died. it was idling in gear at about 250-400 rpms. When the battery is disconnected, the computer relearns idle. when it did this, it relearned idle with the throttle body and mass airflow sensor clogged up which I confirmed when I took them both off. after cleaning those, it now idles around 1000 rpms in park. I need to remove the battery again and I think it will normalize. If you clean the throttle body, make sure you are getting clearance all around the flap so air can go through. the computer before the disconnect had adjusted to that but was messed up upon relearning it causing the issue.

The rear driver side door had no door light turning on and when I removed it I couldn't find the wire for it. I mention this mostly because some people never take their doors apart. for the arm rest, literally just pull up on it and it comes off. Doing that, I was able to get my fingers into the door and pull out the wires that were disconnected for some reason.

1. For the steering wheel vibration, I plan on getting the wheels rebalanced and Im thinking about an alignment because it doesnt quite drive straight like I want it to. Beyond that, are there any common issues with vibrations? im thinking inner tie rods maybe? body mounts? engine mounts?

2. for the slow engine start, I replace the plugs and they run good. Its more of a cold start problem but I've tried it both ways. Its not dragging like a weak battery. it just needs one or two more pulses that I feel it should. I've had multiple people including Toyota tell me that the alternator, battery, and starter are all good. my air intake is clean after the issues with the idling. How could I tell if the starter is actually bad even though people say its not. Maybe a fuel pump issue?

3. My least favorite problem: engine shudder. Ive had one person already tell me to check the engine mounts which I will be doing when I get home. its not a constant thing. it only does it when I start the car, turn the car off, or irregularly when I idle it. Any ideas on this one? or any tips on swapping the motor mounts? I don't have an engine lift but I have a big floor jack and I can use for this.

As to the steering vibrations: I would think wheels unbalanced would be noticable at most speeds, getting increasingly worse as you go faster. Thinking more along the lines of ball joints there.

As to engine shudder: vacuum leak? Do you have any fuel trim info or live data? Don't think mounts, you'd be moving all the time. If you are having issues with vacuum, you could definitely have issues starting too. Don't assume because the engine lags starting that the starter is bad, it's job is simply to spin the engine until ignition occurs. If it's taking a long time to start and it runs like caCa, I would look at vacuum and fuel flow next. OBD2 helps here. Also you mention an 04, so there is always going to be that looming head gasket issue, not saying that's your specific issue, it's just common in your model year. Hope my input helps some, good luck!