2004 Nissan Quest, pressing gas pedal but car won't speed up

I would think the seller knew about this , good luck on that , scan for codes even if the light ain't on

I have a 2004 Nissan Quest SL. It has that same exact problem and I would suggest that the dealer had absolutely no idea. I took mine to my car mechanic several times for it and he could never get it to do it for him. Finally I was having the same problem and (very slowly and with much revving) took it straight to the mechanic without turning it off. He got in and felt exactly what I was talking about. Looked it all over and to this day has no idea why it will do that sometimes. It might go 3 months without doing it and then do it every few days for a while. Very strange but very easy to fix - like you said, turn it off and back on and it's fine! Good luck!

look for a good motor to chassis ground ?

This can be the bottom cat. convertor starting to stop up, after driving for a while. Vehicle will get slower and slower due to back pressure on the motor from the exhaust system. When you turn off the motor the back pressure decreases and allows the motor to function normal after a while. In early stages this may be intermittent, as it progresses it can stop the motor completely and cause blowback in the motor compartment (this is the extreme stage). This is something you can check for yourself, by unhooking the exhaust Cat. convertor piping and starting the motor. If the Cat. was plugging, the motor will run just fine until the piping is reconnected causing back pressure. Unfortunately this particular Cat. comes on the bottom piping from the engine welded in one piece. The quest also uses one smaller cat. ,one for each exhaust manifold. This bottom cat. piping bolts to these two exhaust cat's.Typically the one that plugs is the bottom one located in front of the muffler piping flange. This convertor comes in a one piece piping section. approx. $300. This is something you can do yourself. I had to replace mine, car runs just fine. Of course the other option is to rod out the guts of the cat, crank the engine to about 3000 RPM and blow the guts out the back, then reattach the muffler piping, Car will operate just fine, however, if your state stills does inspections, that's not the legal way. Hope this helps to narrow your concerns.

The there is no cover on bottom of my van motor exposed shouldn't there be a cover and is this dangerous to drive this way

Change the neutral safety switch. Or called gear selector .code reads P0705 It is external. Sits on top of the transmission. Need to remove battery and battery tray. Easy repair 3 small bolts and a wire harness plug. Must make sure van is in neutral when installing new switch and align any tabs or arrows. This happened to my 2004 quest Car revs and moves slow. It’s called limp mode. Tranny is starting in 5th gear. Check gear indicator on shifter may read different than actual gear selected

When I dive my 2004 Nissan quest give it gas to pass a car loss power and then give it gas run slow