I have a 94 fd that I took to a rotary specialist a couple days ago to get a weird sound checked out. Sort of hard to describe the sound but I guess it sounds like a winding sound, sort of like a rattling sound. This happens when I accelerate at around 2K rpm- 2.5K rpm. I can hear the sound all the way through 4th gear. The guy told me that I was running too lean and my best bet would be to get a apexi pfc. I have a dp, cb, and drop in k&n filter on stock ecu. I need a second opinion, can anyone help? Either way I do need the apexi pfc, but can't afford it right now.


-Thanks

 

Well you know what opinions are like.

This is BS. Maybe you are running lean, but if you are then something else is wrong with the car. Adding a PFC is not going to fix anyhting at this point. A stock ECU should be adequate for your mods. I'd take your car to someone else for another diagnosis.

Sometimes deposits on your spark plugs can help reveal if your car is running lean. I am not convinced YET this is problem.

 

I completely agree. At stock boost levels, you can go a bit past these mods on a stock ECU. Your ECU is not the problem if your car is running lean.

Also, did he hook your car up to a wideband O2 sensor? I don't think I would make assumptions on whether someone's car was running lean bases solely on sound.