nyclad

Hey all,


When I hit WOT at about 30 mph I lose power, ruff idle, CEL with the following codes: p0300, p0303, p0305. A few hours later, and after clearing the codes, the car will drive like nothing ever happened. I drove the car for a week without any problem as long as I didn't hit WOT. Yesterday morning I Hit WOT just to see if the problem was still there, and just as I thought, the problem came back, same symptoms and same codes. Fortunately, I was still able to drive to work and park the car. Eight hours later car started fine no problem at all.

nyclad

Any ideas?

Benz-O-Rama

You're having an engine misfire at WOT. Specifically, cylinders 3 and 5. I'd start by confirming a secure connection of plug wires. Also, how many miles on your car? You might need to change plugs and/or coil packs.

http://www.obd-codes.com/p0300

http://www.obd-codes.com/p0303

http://www.obd-codes.com/p0305

nyclad

Hey Benz-O-Rama,

Thanks for responding. I have 98,200 miles on my car, changed all the spark plugs July of this year. I'll check the wires tomorrow, hit WOT and see what happens.


Thanks!

Pekkle

Sorry! What is WOT?

nyclad

Wide Open Throttle

nyclad

Turned out to be the aftermarket crankshaft position sensor I purchased on eBay a few months ago for $35.00

Sunday the car wouldn’t start at all, cranked normally but wouldn’t turn over. So I used my OBD II scanner got the code P0335 (Crankshaft position sensor) replaced it with a OEM CPS from the dealer, and the car started right up, even better than before. Took the car for a test drive at WOT no more misfire or check engine light.

gnma

Excellent DIY diagnosis and fix!!

I will say, it may have been better to ck. codes the first time you got them (u already have a scanner), rather than ck. after the car wouldn't start.

Which scanner do you use?

Tks.

nyclad

Well, the original OEM CPS gave me a code a few months ago (P0335) so, being that the one from the dealer was so expensive, I decided to replace it with one I saw on eBay for $35.00. That one failed also.

I had a feeling something was wrong with it being that the car would take longer to start in cold weather, and start fine in warmer … the eBay CPS never gave me a code at all until it failed on Sunday. Being that I couldn’t get the car to start, I had no way of knowing there was a code (check engine light only comes on when the car is running) so I decided to use my Actron CP9125 pocketScan, got code P0335 again.

So it appears that the eBay CPS was defective from day one i.e. longer cranking in cold weather, misfire at WOT etc.