2007 Yaris Loss Of Power Over Bumps

[Cigar_Maverick]

Hello,
I'm beginning to diagnose what I THINK (always dangerous) is an electrical or fuel delivery issue. What I am experiencing is a loss of power if I hit some "sharper" bumps. An example of when this happens is if I turn off of a paved road onto a gravel road and hit some washboards under normal acceleration, I experience a loss of power in the engine. It doesn't die, just seems to loose about 50-70% of the "thrust" it normally has. As soon as I get past them, it picks back up again. SOOOO, my thought was a loose wire of something like that. I brought the car in the shop tonight to see it I could make it happen while sitting here idling. I lightly tapped on things with a rubber mallet and wiggled wires. I also pulled the plugs to see if I could see anything. Nothing stood out.

Now, this MIGHT be related to the "P0420 Catalyst System Efficiency Below Threshold Bank 1" check engine light that seems to indicate a worn out catalytic converter that came on a month ago. Maybe something is loose in there and blocking exhaust flow?

The only other thing I could think of was that it was a fuel delivery problem. About a year ago I replaced the fuel pump. I wriggled the wires at the connector on top of the tank hoping that it was coming lose. Nothing.

I don't know if it matters, but is is a manual transmission.

Maybe it won't fail unless it is under load?

I'm asking for help to find a starting place to figure this out. I'm a little worried that at some point it won't "recover." If there are any clarifying questions that need answered, let me know. I can always hook it back up to the diagnostic computer again at the local parts store to see if any other warnings come up.

Thanks in advance,
Russ