Hey guys,
I have a 1998 honda accord v6 ex coupe with 210,000
An AEM air intake
Pacesetter header if I remember correctly
Flowmaster full exhaust system
And just had a recent tuneup
And I have recently been getting like maybe 20 mpg mostly highway
Before I was getting maybe 28-30 and its gradually getting worse
Any idea what the problem is or ideas?

 

Is your CEL on? Any codes?

 

Yea its reading for the catalytic converter/o2 sensor but I just
Replaced the converter and both o2 sensors 40000 miles ago why would it be back on?
I think the code is confused.

 

Check for leaks in the intake and exhaust system. Possibly a 'false air' issue.

 

First thing I would change is oxygen sensor. Second would be clean out egr valve and ports.

Ok I see you changed it. Could be an ecu issue. You need to check and see if there is a wire issue with the oxygen sensor.

 

So I took it to a shop that does electric work on the car and I do have a few wiring issues one including a wire that when I blew my horn my brake lights blow and a one connected to the oxygen sensor saying air flow isn't getting the right amount or something like thatfrom what I was getting from him. He said the car thinking its clogged might be my mileage problem should I go ahead and pay him to fix it or maybe just get it full serviced a honda dealer?

 

It's probably in Limp Mode, which would certainly cause a drop in efficiency.