I intermittently get the P0193 code even though my 200 4XKR runs like a champ. No hesitation, starts in an instant, pulls like a train, fuel trims are within spec, mpg is fine and no weird exhaust fumes. I did have a vacuum leak some time ago which I fixed and there is no such error code anymore. I used my OBD2 to get rid of the code but it came back a month later. Is there anything else that could cause it? I thought about a clogged fuel filter but that would give me sluggish response which I don't have.

Thanks for any suggestions.

 

Best I can figure, this code is when the fuel pressure spikes and pushes the reading out of range of the sensor. Fuel pressure is measured taking the intake manifold as a "zero". The situation is that you may be driving under some throttle (relatively high manifold pressure) and then suddenly close the throttle, possibly going downhill (relatively low manifold pressure). That drop in manifold pressure has to be accompanied by the same drop in fuel pressure to maintain the normal 55psi. That is accomplished by a pop valve located at the pump in the tank. That valve sometimes sticks somehow and that message comes up.

I suppose the real fix is a replacement of the entire fuel pump assembly. Fortunately, these fuel pump have come down dramatically in the recent weeks. Used to be several hundred $, now some show up on eBay for about $50.

I would start with a quality injector cleaner (Techron that everyone likes) in the hope of helping that valve in its assigned duty. Usual caveat apply: replace the fuel filter first, and respect the concentration of cleaner as written on the bottle.

Best of luck, keep us posted.