HOW To: tune up Geo Prizm 1995, myself.

Wow ,no posted smog report, (the failed gases) now that makes this 10s harder, and for sure more expensive.....
many post,. why not just add to one post
click comments and add.
or edit one. post.
all engines that fail smog run fine. (so says all owners)
(fine means zero,) in the real world.
what's worse is owning a 1995 in USA, and must get sniff tested.
(cant fool that method) no report by you, (paper)

ignore all statements by all smog testers,
only one statement (it fails!)
all others are lies, guessing and BS.
after all if they were fully trained and skilled they'd have a real job.
a fact. (or they get huge retirements from the state?)
The car needs to be check by a pro.
it needs to be scanned, with a custom scan tool that is not sold in any auto store until 1996 happened.

but if that NOT IN THE CARDS./ no money for a real ASE tech?
then yes, do a tuneup..

1: spark plugs. and new wires, cap and rotor.
2: filters. and fresh engine oil, (the oil can be full of gasoline is why)
3: the cat may be ok, is spending a fortune on that good?
on a wild guess,? like your smog guy quipped?
that be your call. no? (shot gun method or testing) your call.

in a shop they would get the engine running perfectly.
in closed loop hot and light cruise.
A NEW front 02 sensor for sure.
then they test the cat last, the CAT is always last.
i think this car has 3 way cat too, so is really 3 cats in one.
all 3 must work. or you fail... (for sure)


what if only NOX gas failed.????
if yes, we fix EGR first. then CAT last. (they work as a team)
what gases failed matters
and was not stated by you.
in a real shop they can sniff front of cat and rear
and tell you ,
bad engine, or bad cat. in minutes.
or both, sure.

bad engine means
1:engine is bad.
2: EFI controls failing, (fuel or spark)
3: misfires. (even some humans cant hear, omg)
4: and many more. but no smog sheet posted, no savvy.

a pro shop knows the pre cat gas levels that are normal.
if they are, then the cat is bad.
end story.