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Tim's Auto Repair
Tim's Auto Repair, mechanic
Category: Chevy
Satisfied Customers: 15642
Experience:  Have owned a repair shop for 25 yrs.
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Have a Gm. that has 2 codes first one is a PO446 and the

Customer Question

Have a Gm. that has 2 codes first one is a PO446 and the second is a PO300 but the only time it misses is at idle. I run the scanner but it shows no cylinder miss. Any ideas
Submitted: 1 year ago.
Category: Chevy
Expert:  Tim's Auto Repair replied 1 year ago.

Hi, My name is ***** ***** for the delay.

I will do my best to assist you

how many MILES IS ON THE TRUCK?

Expert:  Tim's Auto Repair replied 1 year ago.

what all have you tried/replaced trying to fix this?

Customer: replied 1 year ago.
108250
Customer: replied 1 year ago.
A month ago we put a canister purge valve on it and a gas cap but it had a different code on that one I think it was a PO442 but that is fixed. this time we thought we had water in gas so we tried octane booster but it didn't help.
Expert:  Tim's Auto Repair replied 1 year ago.

hi,

ok tel me,do you feel the miss?

what al have you replaced/tested trying to fix this problem

Expert:  Tim's Auto Repair replied 1 year ago.

ok,,the 442 doesnt come up now?

Expert:  Tim's Auto Repair replied 1 year ago.

what al have you replaced/tested trying to fix this problem,the 300 code?

Customer: replied 1 year ago.
No the PO442 does not come up and you can fell the miss just setting there in neutral. Out on highway its ok so we put octane booster in the tank thinking might have a little water in gas.
Expert:  Tim's Auto Repair replied 1 year ago.

sorry i missed you..

the first thing to do here is to give it a tune up.new plugs and wires.these wires can give a fit and there is no good way to test them,,,

be sure to gap the pugs correctly

1.02 mm (0.040 in)

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PLEASE COPY AND PASTE the link below to your browser, I have uploaded more info on this there please copy and paste the link below to your main browser[INTERNET EXPLORER or FIREFOX]

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https://www.dropbox.com/s/psytrf29gxycqvp/1203-silverado-P0300.doc?dl=0

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if the link doesn’t work that way, try it this way

thanks

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www.dropbox.com/s/psytrf29gxycqvp/1203-silverado-P0300.doc?dl=0

.

Customer: replied 1 year ago.
What about the PO446 code.
Expert:  Tim's Auto Repair replied 1 year ago.

the 446 code is a evap code..this could be caused by a bad fuel cap..or a vapor leak from the fuel tank evap system,,you may need to smoke the fuel tank to find this small leak.

PLEASE COPY AND PASTE the link below to your browser, I have uploaded more info on this there please copy and paste the link below to your main browser[INTERNET EXPLORER or FIREFOX]

.

https://www.dropbox.com/s/wpvladzlzy2t0j1/1204-09-silverado-DTC%20P0446.doc?dl=0

.

if the link doesn’t work that way, try it this way

thanks

.

www.dropbox.com/s/wpvladzlzy2t0j1/1204-09-silverado-DTC%20P0446.doc?dl=0

.