P0328 Knock Sensor and EVAP codes (1 Viewer)

[GremlinMobile]

Knock Sensor 1 Circuit High Input. First saw this code pop up about a year ago and then it went away on its own. It came back on about 2 months ago and has mostly stayed on. Occasionally I'll start the car and all the lights are clear, but then I'll start it next time and they'll be on again. Check engine, VSC OFF, TRAC OFF, etc.. Car seems to ride fine, other than when the code first pops up, it keeps the tranny going into 5th gear.

This code seems to be different from the 033 code I've seen referenced here. I see usually it's an issue with rodents chewing wires. However, I happen to have a bad exhaust manifold leak and it ticks like a bastard. Any chance that that's what's causing the knock sensor issue? I'm obviously being hesitant to take it to a shop on account of the expensive labor to open up the intake manifold, let alone replacing the parts. Sounds like it depends on the shop, because some might only be willing to replace the whole wire harness which can be very expensive, making this repair potentially $1500 or more..
Any chance that fixing the exhaust manifold leak will take care of this knock sensor issue?

 

[Rednexus]

I think it's unlikely the exhaust manifold leak caused the knock sensor code. Most of us have or have had the exhaust manifold leak (including myself) and I'm not aware of any reports of a the leak causing a knock sensor issue.

It's honestly quite easy to replace the knock sensors and harness. Intake manifold R&R should be a few hours of work. There is no need to replace the whole harness, a shop can use a knock sensor pigtail (which is the same as a fuel injector pigtail if you have a VVTI engine - if you are non-VVTI I think they might be different) and splice it into the OEM harness with a few heat shrink connectors. I had to do that on my rig when I unplugged the knock sensor and broke one of the connectors. I think it took me 2-3 hours to DIY it. I'd find an independent shop who knows these rigs and is willing to splice your wiring.

 

[GremlinMobile]

I think it's unlikely the exhaust manifold leak caused the knock sensor code. Most of us have or have had the exhaust manifold leak (including myself) and I'm not aware of any reports of a the leak causing a knock sensor issue.

It's honestly quite easy to replace the knock sensors and harness. Intake manifold R&R should be a few hours of work. There is no need to replace the whole harness, a shop can use a knock sensor pigtail (which is the same as a fuel injector pigtail if you have a VVTI engine - if you are non-VVTI I think they might be different) and splice it into the OEM harness with a few heat shrink connectors. I had to do that on my rig when I unplugged the knock sensor and broke one of the connectors. I think it took me 2-3 hours to DIY it. I'd find an independent shop who knows these rigs and is willing to splice your wiring.

Roger that. Thanks. I called a reputable shop locally and they looked it up and said their system shows this work taking 3 hours and sensor costing 150. 3x145+150 = 585. I just don't even know how this works. Do they order the knock sensor ahead of time and open the engine up when it's ready in their shop, or do they open everything, confirm the fault, and then order the needed parts?

I'm afraid to get into it myself. Never opened up the intake manifold. The craziest I've done is take apart and put together an AHC pump on my LX, replace valve cover gasket, and wheel bearings., alternator, radiator. This seems like next level work though. Plus I read lots of warnings about dirt falling into the intake ports..

 

[Rednexus]

If you can do wheel bearings and an alternator/radiator you can definitely do this yourself. You'll need to pre-clean the area around the intake. Some stuff will fall in the ports, I've gotten it out with a vacuum cleaner and compressed air and verified via shining a flashlight into the ports. You'll also of course want to put rags in them when working on the motor. I think my intake has been off 2-3 times now .

I'd imagine they'd have the parts on-hand and send them back if they don't need them. TBH $585 total with $150/ea for the sensor is a very reasonable price for this work, especially from a reputable shop. I'd expect them to bill you an extra hour or labor and maybe $50-100 in parts if they also have to replace some of the wiring.

 

[GremlinMobile]

***UPDATE

Took the car through a car wash yesterday and on the drive there and back noticed a marked sluggishness. It seemed to hesitate upon acceleration before getting to 3,000 RPM or so, and just generally didn't behave like itself. I figured I'll scan for codes again and see if there is anything new. Sure enough, besides the P0328 code I've been getting for a while, now I am showing P0441, P0455, P0456.

P0441 - Evap emission control system incorrect purge flow.
P0455 - Evap leak (gross)
P0456 - Evap leak (very small)

Here are the techstream readings. I'll admit I don't know how to make sense of this. Hoping someone can tell me if this tells a tale. The first screenshot is with the AC's running, so higher RPMs. MAF reading is higher than the second screenshot which is just idling with no AC on.

Where can I start troubleshooting the EVAP codes?

And do they have any correlation with the knock sensor codes I've been having?

Thanks in advance.

 

[GremlinMobile]

Bump