93 with awful gas mileage

[eagerinsight]

My 2.2 93 is getting 15 mpg !! I need to do a little tune up (cap, rotor and air filter) but everything else is up to date. Do I need a O2 sensor, because I never got a CEL?? Timing belt is a year old, new plugs and wires, fuel filter and pcv valve all new. Am I missing something, 15 mpg in a 4 cylinder is hard to believe. Seafoamed it last month before oil change, and the car is not driven hard.


PS. how many O2 sensors do I have? Should I replace with a heated O2 if needed?

[Venom_5]

i dont think it has anything to do with ur O2 sensors if youre not getting a CEL

ur engine could be filthy ... ur spark plugs could be fouled ... there are like a million things to check

how does ur engine bay sound? any weird noises or vibrations?

[eagerinsight]

I hear some tapping, no knocking or pinging.

[Durrby]

It wouldn't hurt to do a tune-up but i'd say the o2 sensor is the culprit for the aweful mileage. Before I replaced mine I was getting about that. After I replaced the one on the exhaust mainfold it went up to like 21mpg. Now I average like 25-26mpg, but it's mostly city driving with a very lead foot.

[eagerinsight]

I have had the car for 3 years now, it has 188k. I bought the car from a friend of my family who was the original owner. I checked all of his service records (he saved them all!!) and I couldn't find any record of the O2 being replaced. I would hate to replace it if the sensor is still working. I will perform the diagnostic test on it in the morning.

[Durrby]

Dude your at 188k, I needed to change mine at like 65k. Believe me it'll pay for itself within a few fill-ups.

[louie1086]

replacing your 02 sensor is a worthy investment, despite the cost. its not replacing cuz its broken but because its worn, thus poor performance leading to inferior overall performance. replace the damn thing!!!

[eagerinsight]

Is there only 1 sensor or is there another sensor before the cat. Should I buy a heated one?

[Durrby]

Originally Posted by louie1086

replacing your 02 sensor is a worthy investment, despite the cost. its not replacing cuz its broken but because its worn, thus poor performance leading to inferior overall performance. replace the damn thing!!!

exactly, and a worn O2 sensor will not trip a CEL.

[eagerinsight]

Where can i get a O2 sensor cheap? Toyota dealership wants 160, I found a lot of them on partsamerica but some are OE and some are universal. Will they all work?

[geoff5093]

Originally Posted by eagerinsight

Is there only 1 sensor or is there another sensor before the cat. Should I buy a heated one?

There is one before the cat on the I4, and two before the cat on the V6. In addition to the one near the cat.