P0404 Honda - No lights (engine, VTM-4, etc), but engine won't rev over 1,000 RPM.

Question

I recently replaced the timing belt on a 2007 Honda Ridgeline, along with all six coil packs, and installed an entirely new exhaust system (including all three CATS, Y pipe, muffler, and tailpipe). Everything has been running fine for the past three months, then it suddenly stopped reving over 1,000 RPM. Checking codes, I found a P0404 code, but nothing else (no misfires, or anything; not even a check engine light). During a visual inspection to see if a vacuum leak developed (none were found), I noticed that there was a hole in the exhaust pipe of the rear CAT, just below the downstream O2 sensor, and I repaired that. I reset the code in the computer, and disconnected the battery for several hours (just to be sure all codes were gone), but there was no improvement; it still won't go over 1,000 RPM. Any suggestions?

Answer 1

P0404 Exhaust gas recirculation (EGR) control circuit range / perfromance problem

The engine not breathing right a P0404 is just the result. Clearing the code will not make a differenct what you have is a mechanical conidition either the timing is off a tooth or two.( it does not have to set a cam to crank code) or the exhaust is pluggged.