Trouble code po351 engine stalls, tach also goes

P0351 OBD II Trouble Code

The first part is magic, (EFI system and good engine)
but?????
gauges go off can be a bad fuse or loose fuse to cluster.
when any Gas engine stalls. the RPM drops to 0
the EFI sees that and goes to key on, not started self test.
this is covered in the operator guide.
key light comes on KEY LIGHT, HUMMMMMMM
Let me look at the waring lamps, there are many.
one light is engine overheat that is logo of a thermometer but looks
just like a key.
http://dashboardsymbols.com/the-symbols/
is this a engine stall post
or engine runs perfect all the time , but only my dash acts funny
you didnt say?

key lamp?
immoblilzer (big trouble there)

a stall is anytime engine RPM drops to zero. called a STALL.
if your cars engine stalls, post that way, the lamps are all normal
on at any stall, on any car.
at a stall , rpm goes to zero and MPH drops to zero as you coast to a stop , stalled. that is all normal for any stall.

if engine stalls.
that is complex.
here is list.

1. lost 12vdc power to EFI system. (battery died, fuse blown)
2. never gave your car the 60,000 mile tune up, see opr, guide.
3. bad fuel.
4. overheated the engine.
5. engine oil gone, never ever checked at each fill up.
6. other more complex EFI system parts failures, ASK.

Have the automatic idle speed control valve cleaned.

What year is the vehicle ? The tach gauge probably is going out . GM has had insturment cluster gauge problem's . Faulty stepper motors .

There are a million web-sites out there that offer free listings of the trouble codes. Go to Google, simply type in trouble codes for your year VW, model and engine size, you will get multiple listings.

sounds like this engine light has been on for a while and codes are piling up, lets start with the po351, note all codes should have a po or a p or b in front of #s.anyway lets go, first is po351 which means you have a bad # 1 ignition coil, replace the coil and check the connection and this will solve that code. next is po420 cat eff below threshold, this means the converter is not working good anymore, but bad oyxgen sensors will cause this code if they are bad and not reading exhaust correctly, you will need to have the o2 sensors tested and also make sure converter is not rattling loose inside shell if it is then cat is bad not o2 sensors, and last code is po545 is ac clutch relay circuit this may be due to a bad ac compressor clutch a blown fuse or bad relay. hope this info is helpful.

It could be the crankshaft position sensor. I have a 2001 Grand Prix, and when the crankshaft position sensor went out, the tach would drop to zero, and the car would act like it wanted to stall for about a second.

I have had the almost same problem twice. A 'thump', like the engine missed a fire and tach drops. Seems OK after restart. Electrical? Timing chain slip?
Has 135,000 mile. Any clues?

Check engine codes.
If it comes up as a Crankshaft sensor... Replace it.
These are the exact symptoms

If the vehicle cranks normally when not starting check the tach see if it is reading any engine speed. Sounds like the crank sensor is going bad very common fault on the 3800 series 1 & 2 engines. You must remove the harmonic balancer to replace the sensor.