Hi,

I currently have the following misfire codes on my 2000 acura TL: p300, p301, p302, p304.

Originally i was getting p302, p304, p305 and p1399. This occured within 50 miles after filling my tank with regular unleaded fuel. I had been using premium unleaded until then.

I got the spark plugs replaced (NGK platinums)and got a fuel system service done at Sears. This is supposedly better than just putting in the fuel injector cleaner into the fuel tank when we refill.

With all this done i was no longer getting the misfire codes. Interestingly enough, these misfire codes showed up almost immediately after getting the smog check done!

Any idea what is going on and what i should look at fixing next to avoid the misfires? Neither of these misfires started with cold-start. They were always with a warm start.

Thanks in advance for all the advice.

 

Welcome Rajp !!!
>Some basic questions that might help provide more info concerning "Misfires". :

~So, were ya getting those misfire codes prior to the "Sears" servicing ?
~Were NGK plugs used to replace the old ones with ?
~Were the coil packs checked yet ?
~Have the EGR passageways and TB intake been cleaned recently ?
~Have the electrical and vacuum connections been inspected ?
~How's the car's idle speed when warmed up ?
~Have ya topped the tank off with premium yet ?
~Was the CEL reset after repairs were completed ?

 

Hoe many miles on your odometer?

 

I would remove the EGR plate and inspect it for blockage of the passage ways and ports, if its dirty clean with carburetor cleaner and scrape the crud off. If it was never done chances are its starting to clog.
Use the highest octane available at the pump to avoid issues.