Captain Sweeney

So to start my engine started shaking noticably after I put in a new steering rack. I got it aligned so that's out of the way. We checked the engine codes, and we got some cylinder misfire errors. So, got new coil packs. The errors went away but it still seemed to be shaking a little. So we checked again and got o2 sensor errors. Figured it was fine to drive since that only affects efficiency. Found out recently that the cats can get gunked up if I don't fix the o2 promptly. So today I checked again( the codes) with an obd 2, as I did the previous times, and now I'm getting p0303, p0304, p0305, p0300, and p1205. The p1205 stated that it was a "manufacturer controlled fuel and air metering" code. The rest of those codes stated that they were cylinder misfires, of the corresponding cylinder, so 3,4, and 5. I have the USA model, I know that makes a bug difference in checking for problems. I also noticed that it does seem to have performance issues, not accelerating as fast as it should, and vibrating badly when at certain speeds coupled with throttle position. I just keep getting more problems the more I fix.

2001 S8

Couple of things leading to a shaking engine/not preforming. Check the following:

• You replaced coils but did you check the spark plugs? These are easy to change out and just good to do if unsure when last changed. audipages Replacing A8 Sparkplugs
• Engine mounts, especially the front mount. Mine was bad when I got my car. At stoplights with car in gear, I could feel the engine shaking and my steering wheel would vibrate, as well.
• Vacuum pods at the front of the engine. Look for broken plastic arm(s), or one pod compressed and one pod inflated. If not working car will not accelerate like it should.
• Kick-down switch is in correct position. Behind the gas pedal, there is a plastic cylinder. This controls your "kick-down" of the engine. With car off, push down on the cylinder, if you get resistance then a sudden "click" with more movement to the floor. The "kick-down" switch is turned on. If you get a fluid motion all the way to the floor, the switch is turned off. If turned off, turn the cylinder counter-clockwise a quarter of a turn to activate the "kick-down" function. You'll feel and hear a "click" when you turned it far enough.
• Vacuum hose(s) leaking. These tend to get loose or breakdown over time and will cause engine issues. audipages 40 Valve Vacuum Hose Replacement

Good luck.

jfrahm

Good advice. Sounds like a big air leak to me. Disconnect in the air intake tube, broken/loose connection to the intake, PCV issue, brake booster line, etc.

Captain Sweeney

I replaced the spark plugs a few months ago, iridium spark plugs from AutoZone.

About the engine mount, it never shook bad before the work I did on the steering rack. So I do suspect maybe we damaged a vacuum line.

Also, we were working on it and found that their were some empty slots where tubes used to be. They connected from the bottom of the engine block to the top of the valve body, on both sides, towards the rear of the engine block. They were completely corroded and gone, not even connected, so we put in new ones. Im thinking something down there got shoved off something it should be on, or maybe we connected tubes to the wrong things?