new qx4. new to site. new problems

[nickmccomb1]

hi i just bought a 98 infiniti qx4. after driving it for about 75 miles, check engine light came on. had 2 codes P1440EVAP Canister System Small Leak (0.040") and P1336Crankshaft Position Sensor Circuit Malfunction . it had problems such as very rough staggering idle and strong shaking when idleing in drive or reverse. also at highway speeds while just cruising at 45-70mph, i would expierince jerking, sometimes very heavy, when my foot was on pedal maintaining speed, it also affects the rpms. i replaced the crankshaft position sensor, erased codes, took it for a drive. idle seems to have greatly improved, but jerking on highway is harder then ever. also new code came up. P0335(Crankshaft Position Sensor Circuit Malfunction).
another thing is the distributor is making a clicking noise, wich increases when giving throttle. you can also put your hand on the cap and feel it hitting something along with the clicking/ticking.

so my questsions i have are, is the jerking related to either the crankshaft position sensor or the evap canister? or an entirely different problem all together?
why am i getting a different code after replacing cps, that is meaning the same thing? could it be a faulty sensor i put in? or could i have shorted a wire?
could the ticking noise in distributor be causing problems, without sending a code

1998 qx-4 with 130000 miles. bought a couple weeks ago with no check engine light. came on aprox 75 miles of driving. yes im someone who got screwed buying a car off craigslist. i am using a craftsman(innova) obd2 scanner with the online diagnostic reports.

any insight to what his problem could be would be greatly appreciated. thank you

[Slumpert]

Hi Nick... I feel your pain as I too recently purchased my pathfinder off craigslist and the PO had hidden the problems from me as well.

At this point, assume they have done nothing maintance wise to it unless you have actual receipts for work done.

From what you typed above, the first thing I would look at from now would be the transmission. Follow the guidelines for checking the fluid level, but also really look at the color of it.. If it is at all like strawberry milk, do not drive it at all.. Some radiators can fail and allow coolant into the transmission fluid and that destroys them quickly.. More of a issue with latter modles but always a silent danger.

Consider flushing out the current fluid and putting in what you know is the correct compatible fluid..

The MAF sensor can cause all sorts of uneven running and spending 5 minutes to remove it and directly spray it with MAF cleaner spray might make a world of difference. Don't worry about trying to wipe it with a q-tip or something.. That only raises your chance of breaking it 1000%.

I would replace the cap and rotor right away.. There is not supposed to be any noticeable clicking going on.

Again I can't stress this enough.. If they hid stuff from you, you can't trust that anything is correct at this point. I found my airbox was not even clamped closed......

If you live in Houston area I would be happy to help you as I can.. At 130,000 miles do you have proof the timing belt was replaced yet?

[Towncivilian]

What brand of sensor did you use? Is P0335 the only current code?

[nickmccomb1]

Sorry to ask questions and not respond, but fiance just had our second daughter, the reason I bought an SUV. I appreciated the quick responses though.
I do plan on buying a whole new distributor right away. All my fluids look fine. I will.clean the maf asap. And I bought a duralast sensor from autozone. And yes now my only code is 0335.
I also wanted to mention the jerking feels like it comes from the rear end? Like something locks up for a quick second and kind of drags the car.