Engine running rough and engine and hold light flashing

[mpk4463]

Ok I have a 2005 LS HB with 190K on it. I am having rough engine issues. I have replaced the plugs, plug wires and coil pack. On the coil pack I did notice that cylinder 2 was rusty when I replaced it. So after replacing all this I still get the engine and hold light flashing and rough running. When I first start off in the morning there are no issues. I drive for 5 miles to get coffee and when I restart the car is when it happens. So I have found that if I turn off the car in neutral and restart the lights stop flashing and car runs fine for the rest of my drive into work.

For the drive home its fine until I get in bumper to bumper traffic (15 miles or so). Then runs rough, lights flashing. I just will continue to drive in traffic and after a few minutes it stops and all is good again.
Is there something electrical that I am missing? I am at a loss and don't want to really pay for someone else to work on it just yet.

[Daox]

Go to and autoparts store and have them read the code that is turning your check engine light on. It is a free service they provide.

[2010AveoLT]

is just the hold light flashing or is BOTH the Check Engine light and the Hold Light Flashing? if the Check Engine light is Flashing, you are quite possibly doing VERY Expensive Damage to your Catalytic Converter!

[mpk4463]

Ok I had the codes checked. Here is what they are, P0300 and P0463. Where do I start?

[petrified.rabbit]

the p0463 is the fuel level is off. I think I get this code every time I get a low fuel light, however, this code does not trip a light on my car..

you have an p0300 which is misfire. I would exchange your coil pack, and double check your work. It is very easy to damage wires etc. but if you bought cheap replacement parts, they might just not be good. first and foremost, what type and brand of spark plugs did you get? I had a set of autolites put in my car and i couldnt make it home.

[mpk4463]

I was told that the P0463 could be my fuel pump which would cause the rough idle and rough running in traffic and stopped at lights. As for the P0300, I have rechecked my work over and over. No arching. I put in a good set of Bosch plugs, good wires and a new coil pack.

Question, pistons run 1, 2, 3, 4 from left to right as you look at the motor. They connect to the coil 1, 4, 2, 3 according to what is labeled on the coil pack and what I have read. Would this be correct?

[avguy]

I was told that the P0463 could be my fuel pump which would cause the rough idle and rough running in traffic and stopped at lights. ...

No personal experience with that P0463 code, but after reading the doc, I'm not understanding how a fuel level sensor high voltage is being caused by a bad fuel pump. And since the pump is over $200, you should do fuel pressure testing before hanging on one of those. Has the throttle body ever been cleaned? This a fairly easy DIY job, and you also should consider removing and cleaning the TPS and IAC (either of which could be causing the P0300 at low revs), as a part of that cleaning. If that helps but not all the way, then maybe replace one or both of those parts (around $25 and $50 respectively).

[mpk4463]

Ok sounds like I have some things to try. TPS, IAC.....???? What are they and where are they?

[avguy]

Throttle Position Sensor and Idle Air Control valve. They are both attached to the throttle body with small screws, and are removable on the '05. Based on your problem description, it would seem more likely to be the IAC but both of these can get really gunked-up from all the sludge accumulating in the throttle body, especially an 8 year-old vehicle with 190K. The required standard disclaimer here is that your problem could also be cause by a number of other things as well - misfire has quite a few possible causes. But the throttle body cleaning is something fairly easy to try, and best of all the only cost is a can of TB cleaner.

[mpk4463]

Well I will give that a try tomorrow. Any answer on the plug wiring I asked about?