Jonnybob

MPG has suddenly dropped from 17 to 13 and transmission was not shifting well. Changed tranny filter/fluid and shifting is back to normal but MPG is not.

No CELs. Changed O2 sensors within the past year and just cleaned MAS.

Any thoughts on what to check next?

salimshah

How are you checking mpg?

Salim

AnthonyMtz

Hello, welcome to the forum, have you cleaned the throttle body? Also have you changed your spark plugs? Lastly I would do a MCCC engine treatment, it helped my rx run smoothly again, best of luck!

Jonnybob

MPG per the dash gauge.

It's the wife's car. She said the car was feeling sluggish and not shifting correctly. There was. CEL for a shift solenoid so I started with the basics an changed the filter & fluid (4 quarts). Cleared the codes. It shifts fine. But the mpg has not returned. To her it feels sluggish. To me it feels as peppy as ever (well, as peppy as #25/hp can).

Thanks.

Jonnybob

thanks for the reply.

I clean the TB every oil change but did another when this issue arose. No change.

Car idles smooth and comes off idle fine so I don't suspect it's a plug/wire issue. The engine treatment could only help so I may try that.

fastnoypi

how does it idle? funny idle or very low may indicate a clogged or damaged catalytic converter