Hello-

I have noticed slightly last year and especially this year my 2000 GA 3.4 V6 has been idling roughly and also accelerating with hesitations. It seems to surface more during colder weather. I also noticed recently when I come to a stop and decelerate the car lunges a small bit as if I'm tapping the accelerator once and then idles to normal. Once and a while it will actually dip so low after decelerating on the RPM my power dims or even shuts the car off. It always starts right back up again afterward. I have a few codes that were scanned but haven't been able to set aside the money to pay for a mech to fix it. The one that comes to mind is the knock sensor, though I should re-scan and write them all down.

I am an intermediate with working on my car and wondered if I should just replace the Knock Sensor since that's what came up as one of the main codes. I've heard O2 sensors sometimes can trigger these issues as well and make the knock sensor come up. I have noticed over the last year or so a bigger decrease in power and acceleration.

The car has 180,000 on it and I haven't replaced any sensors as of yet. Are these jobs pretty easy? I have a Chilton's guide if it's a fairly simple job. I'm close to wanting to replace the car but if I can squeeze 200K out of it I'm surely happy with getting the most out of this good car. Nothings better than a paid-for car right?

Any suggestions would be appreciated!

One more thing to add-

Is it easy to replace O2 sensors and the knock sensor?

Have the car scanned again and post back what codes you have. A knock sensor can send false signal if other things are creating problems. Same as o2 sensors. If it reads rich o2 it could be a number of things instead of just a bad o2. Get some codes and it can make helping you a little easier.

OK.. sorry for the delay, but here's the verdict. There's 4 codes read.

Mind you I'm at 180K and no known sensor replacements thus far.

1. P0336- Crankshaft position sensor condition

2. P0327- Knock sensor condition

3. P0442- EVAP (evaporative emission system) small leak/no flow condition

4. P0341- Cam sensor condition



There you have it folks. I replaced the gas cap as a cheap and easy first step on the EVAP code, not sure if that's it.. but it's a cheap start.

Again- My biggest problem is random hesitations at idle and at accelerating up to speeds. Once the car is at my desired speeed (ie 65mph) I'll occasionally get little hiccups that don't have a pattern, just random every 5-10 seconds. It hasn't stopped from running yet.. but I do notice this problem resurface while in colder temperatures outside, nothing to do with engine temperature. I don't even remember this happening in the summer this year.

Any suggestions or help is appreciated. I'd love to do this myself if I can as a slightly better than beginner mechanic :P .. But if it's extensive I'll just have to leave it to the pros.

Thanks!

If the 24X crank sensor and the Cam signal are not present P0327 will set.
So It is simple solution for you - do not do anything with knock sensor.
Inspect all the wires for the 24X crank sensors first (the ones that connect to the ignition module and its connectors, and then inspect cam sensor wires and its connectors. You will find instructions by XI in maintenance section how to test them both.

24X sensor is harder to replace than 7x since you will have to remove crankshaft balancer, and if you do not have impact gun you will have to use one nice trick.

http://www.youtube.com/watch?v=S_-FsVvNr40

So the crank sensor would be the be thing to check/replace first?

So the crank sensor would be the be thing to check/replace first?


yes

So I brought my car in.. they say around $500 to replace both sensors and also said the knock-sensor is a ceramic type sensor and it's "starting to crumble". They also said instead of their part supplier they recommended OEM from GM for the CPS stuff since they had a return from someone who had an aftermarket replacement.

This price sound about right?

I would not replace knock sensor, as I said if you don't have a crank and cam signal it will trigger code for knock sensor. Cam sensor you can replace yourself if you know how to remove power steering pump

We just did the crank sensor for now.. I said if I can't replace the cam sensor myself I'd have to bring it in. My adventurous side wants to do the cam sensor.. but my having fun on the weekend side doesn't. I'll have to pull out my HAYNES book and see how bad pulling the pump out is. If I can tackle this in a few hours, then I'll do it. I haven't taken anything off of the belt area as of yet.. so I hope it's not too bad.

The shop said that they replaced the crank sensor and reset the code it worked great then the sensor went off again and the "safety mode" or whatever he called it when the code went off again made the car run the crappy way again. So from what I gather the hard one is taken care of, and I'll have to try to replace or bring it in for the cam sensor. We'll see what comes up. Updates ahead..