backfiring

[CapoTexan]

i have an '02 capo that has been in a garage for about 18 months. i am having trouble with it reving around 3Krpm and it is also backfiring.
I have updated the map and it didnt help. i checked the airfilter and it has some "blow back" on one side. the throttle body is clean on one side and a little dirty on the other (from the blow back obviously).
can anyone give me an idea on things to try?
could it be throttle body alignment?
does the blow back mean that something is really wrong, or is alittle ok?
any help would be appreciated.

[Ergo]

18 months!

1. Gas quality???

2. Spark plugs may need to be replaced.

3. Is your exhaust stock?

4. Rats nest in the airbox?

[CapoTexan]

no rats nest, i checked
the fuel is new 93octane
stock pipes, the tuneboy diagnostics said that the spark plugs were firing fine
it looked as though my throttle body might need to be aligned(according to the IACV reading on the tuneboy software)
could this be the problem?
how could they get misaligned from sitting in the garage?

[monoi]

When you say aligned, you mean balanced ?

[CapoTexan]

yes
actually i think the correct term is syncronized

[monoi]

Have you put in new fuel ? Add some cleaning additive.

The throttle cables are moving freely ?

The spark plugs are fine ?

I cant see myself why they would go out of balance, and in any case that has a lot more effect at idle than with the plates open.

Any error codes ?

The blow back has more to do with mixture problems, and it is likely that over 18 months, soem residue has formed.