So im pretty sure its a bad o2 sensor, my 95 saturn sl2. This car has 240k miles , dual cam, and automatic transmission.


Im getting about 15miles per gallon and sometimes when i try to accelerate it will bog down until i let off the throttle , then it will catch speed just fine.Also I can smell wet raw gas , but looked and there isnt any leaking anywhere.

I did the paperclip trick to read the codes after a check engine light came on, got a code 13.


Tomorrow im going to replace the upstream o2 sensor( the one on front of exhaust easy to get to, and a cheap part)

anything else i might should consider?


also just a side note: I ran some seafoam through the car (1/3 in tank 1/3 through vacuum line 1/3 in oil) a couple days after i bought it, and then it started having the lousy mpg problems.





please help, the whole reason i bought this car is for its exceptionally good gas mileage, if its only getting 15 mpg i might of well just kept my big *** v8 suburban

 

There is no downstream o2 sensor on an Odb1 s car. Replace with denso part for best results. Your o2 may have gotten fouled by the seafoam or was pushed over the edge by the experience

Also consider ects and connector change per the sticky in the forum. Failure of these wreaks havoc on air/fuel mix and thus gas mileage.

 

In addition to what derf said, maybe a tune-up and a good cleaning of the throttle body would help too.

 

Could be either part. Just remember to change the electrical connector along with the ECTS -- a few buck more, but serious insurance ...