Hey yall, recently in my honda fit 2007 with 185,000 miles I've developed a very big loss of power in just a few days. Car will shift to the final gear at 75-80 and gradually lose rpm until it downshifts, then the rpm gets real high 3000-4000 till I get back up to 80 or so then it downshifts again and I lose RPM, accompanied by a rattling noise at around 3500rpm that I'm hoping is just maybe the bracket for the injectors being. this repeats for pretty much my whole commute (10 miles or so)

It has also been hesitating and lunging at lower speeds. This car has been running rich since I got it maybe 5 years or so ago (normally around -10% but swings wildly) but never throws any codes, and since I have had the car the GPM has been very bad compared to the numbers it should be. I normally get maybe 28gpm driving almost exclusively on the freeway. Wondering if any of you guys have anywhere to start looking or common problems that could relate to this.

Weirdly enough there is no check engine light or anything. Tomorrow I'll check out some stuff and try to get back on here, but I want to say in the last 30k miles or so I have changed the spark plugs and boots, and did the valve lashes.

 

Check your work
Spark plugs tend to leak
Make sure that Spak plugs are purchased from reputable source and exactly the same make part number that shown on the original plugs.
Aftermarket coil boots are inferior to original

 

Ended up being a plugged catalytic converter

Previous owner had used the spark plug fowler trick to keep back o2 sensor out of stream and prevent the p0420 code,

Basically I took the cat off and it took water like 30 seconds to trickle flow from one side to the other, replaced it and I am good to do