Help with a misfire issue

[meyers]

I have a 2003 TT Quattro with the 1.8. I am having a multi cylinder misfire condition, "16684 - P0300 Random/Multiple cylinder misfire detected " "16685 P0301 Misfire Cyl 1" which is throwing a check engine light. I pulled the codes in vag-com, and looked at the measuring blocks. It is showing a misfire on cylinder 1. I changed all 4 coil packs and it went away but soon came back. I pulled the plugs and changed them, and swapped the coil packs around. Still a misfire in CYL 1. I then even tried swapping out fuel injectors, to make sure it was a fuel issue. The light came back. I can reset it and it may not come back right away but within a day it comes back. Any help is appreciated

[MacFady]

I would carefully inspect the wiring harness to the coil packs, starting with cylinder 1. At least now you have a full set of extra coil packs to carry with you.

[MrWick]

My 1.8T is doing the same I haven't registered my vcds yet so can't check measuring blocks. It's say multiple random misfires. I've changed plugs (and gapped), and replaced ignition coils. I inspected my coil harness and found I had some hardened and cracked insulation (and parts missing) on some of the wires so I ordered a new one. The harness doesn't appear to be shorting anywhere though.

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[gofast]

Hi guys; I just purchased a 2001 Audi TT 225hp convertible I get 3 codes including the random misfire P0300, cyl. #1 misfire P0301 cyl. #3 misfire P0303. I have purchased an OBD II scan tool with ABS bout $140.00 and it gives me the same read out I first took the car to Autozone and on the print out above random misfires it says to inspect for faulty vacuum hose so I started checking my hoses and found quit a few dry and brittle hoses have replaced those but then the battery went dead and lost all the memory in the (Auto check system) So Im told the car has to be driven for almost 100mi. of both city and highway driving. now just sitting in my driveway the car has sprung a leak and all the coolant came out. Im getting a little worried because its the first Audi I have ever owned and it wont pass smog and the other problems so I dont give up easily and I am determined to fix this car Im retired and would love nothing better than to learn about this automobile any coments or advise would be most welcome THANXS L.A.

PS. I tried to upload an img but couldnt get it rite

[MrWick]

Hi guys; I just purchased a 2001 Audi TT 225hp convertible I get 3 codes including the random misfire P0300, cyl. #1 misfire P0301 cyl. #3 misfire P0303. I have purchased an OBD II scan tool with ABS bout $140.00 and it gives me the same read out I first took the car to Autozone and on the print out above random misfires it says to inspect for faulty vacuum hose so I started checking my hoses and found quit a few dry and brittle hoses have replaced those but then the battery went dead and lost all the memory in the (Auto check system) So Im told the car has to be driven for almost 100mi. of both city and highway driving. now just sitting in my driveway the car has sprung a leak and all the coolant came out. Im getting a little worried because its the first Audi I have ever owned and it wont pass smog and the other problems so I dont give up easily and I am determined to fix this car Im retired and would love nothing better than to learn about this automobile any coments or advise would be most welcome THANXS L.A.

PS. I tried to upload an img but couldnt get it rite

Is it no longer throwing any codes?
If it's a persistent problem than the CEL should come back on pretty quickly. I've cleared mine and driven over 100miles before it decided to show back up, but other times it comes on again after less than 5miles.
What all have you diagnosed? Any other codes?
I'm no certified mechanic and I'm new to the Audi tech as well so you're welcome to take me with some salt...

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