Fuel economy suffered with inferior plugs! HELP!

I'm a newb here - and to used cars for that matter. But I was fortunate enough to purchase a 1997 Camry last year as an everyday driving replacement for my Avalanche (for obvious reasons).

However, I recently got a tune-up where they replaced the spark plugs and wires with Bosch plugs. I didn't think anything of it at the time until I was forced to come here and research what I have been noticing since:
1. My acceleration sucks now.
2. My gas mileage sucks (getting a measly 20 mpg when for the last year I'm used to getting 380-450 miles per tank).
3. I smell a stronger gas smell coming from the exhaust (as if to be inefficient).

Am I correct to assume these problems were due to the spark plugs?

I have read that it's recommended to go with NGK or Denso, but I haven't found any specifics here as to what the performance differences are, or what the consequences are for choosing Bosch plugs.

Is my assessment accurate? If not, please help me!

Oh... and btw its a 2.2 4clr. with 132k miles.

Yes, the Bosch plugs will adversely affect your engine. Use the factory recommended Denso (PK20TR11) or NGK (BKR6EKPB-11) plugs.

I haven't found any specifics here as to what the performance differences are, or what the consequences are for choosing Bosch plugs.

Is my assessment accurate? If not, please help me!

you found out first hand:


I have been noticing since:
1. My acceleration sucks now.
2. My gas mileage sucks (getting a measly 20 mpg when for the last year I'm used to getting 380-450 miles per tank).
3. I smell a stronger gas smell coming from the exhaust (as if to be inefficient).


get NGK platinums. They're fairly cheap, and will last a long long time. Don't get anything with more than 1 ground electrode (+2, +4), it's a waste of money on your engine and probably does more harm than good.

:screwy:
Thank you so much guys, I'll get the platinum NGKs.

Don't get anything with more than 1 ground electrode (+2, +4), it's a waste of money and probably does more harm than good.

That is not a good generalization. Toyota insists on double electrode plugs on many of its engines. Not recommends, insists.

Not on his engine. I mentioned it because i remember reading somewhere that a double electrode was originally recommended, but then it was changed to the single electrode, so he should avoid it. nevermind the $$

I also vaguely remember a thread in which someone mentioned they had problems with +2, but I might be making that up.