Knock Sensor CEL Woes, Running like crap (1 Viewer)

[acai]

I have been at this for a week and a half and still can't get my truck running right. Here's what I did:

1. PHH
2. While I was doing that I accidentally broke off knock sensor entire connection
3. Installed new knock sensor, but sketchy old connector, Code 55 and no power
4. I soldered in a new connector so now it's new sensor and connector, still popping CEL and running like crap

And various attempts at temporary fixes in between.

At this point I'm ready to take it to Top Line tomorrow and see if they can figure it out since both the sensor and connector have been replaced and I can't take my truck over 1800 rpm without it flipping out. I don't hear any knock from inside the cabin or listening to the engine run with the hood up.

Has anyone had a similar scenario?

 

[landtank]

When you say new sensor, this is a new oem sensor

 

[acai]

When you say new sensor, this is a new oem sensor

Not OEM, it was the $30 eBay one and I made sure there was no continuity through it per the FSM.

 

[baldilocks]

Where are you in CA? I have 4 extra, known to be good, Knock sensors. You could slave one in if you live close enough.

 

[acai]

Where are you in CA? I have 4 extra, known to be good, Knock sensors. You could slave one in if you live close enough.

Hey, I'm in Fountain Valley in Orange County.

Thanks!

 

[baldilocks]

Hey, I'm in Fountain Valley in Orange County.

Thanks!

I'm near Sacramento. I would try and oem knock sensor next. There are certain types of parts that I won't buy anywhere else. And, Honesty, I would replace both.

 

[acai]

I'm near Sacramento. I would try and oem knock sensor next. There are certain types of parts that I won't buy anywhere else. And, Honesty, I would replace both.

Thanks for offering though, and I think at this point I'm going to have to do that. If OEM works out then I think I'll have learned my lesson, haha.

 

[landtank]

I bought multiple aftermarket knock sensors and none of them have worked.

PM me if you are looking for a pair of OEM ad I can help with good savings

 

[alia176]

Rick,

Do f'ed up knock sensors cause the engine to run this badly? If this is indeed the case, he can unplug the sensor connector and the engine should straighten right up, no? Aftermarket sensors may cause the CEL code but I'm having a hard time understanding why the engine would run so poorly.

I'm thinking something else is up and we're focused on the knock sensors.

 

[acai]

Rick,

Do f'ed up knock sensors cause the engine to run this badly? If this is indeed the case, he can unplug the sensor connector and the engine should straighten right up, no? Aftermarket sensors may cause the CEL code but I'm having a hard time understanding why the engine would run so poorly.

I'm thinking something else is up and we're focused on the knock sensors.

I have very limited experience, but from reading the FSM I found that when the engine hits 1800 rpm and the ECU reads that the knock sensor error then it retards the timing.

It was working fine before I did all this PM :/

 

[NLXTACY]

Broken wire inside the casing? I'm going thru the exact same thing right now.

 

[acai]

Broken wire inside the casing? I'm going thru the exact same thing right now.

That's what the original looks like haha, new $30 eBay special is a suspect dud, and a new OEM one is on the way, should be here Saturday.

 

[NLXTACY]

View attachment 1457981

That's what the original looks like haha, new $30 eBay special is a suspect dud, and a new OEM one is on the way, should be here Saturday.

Yeah I have new OEM on both and repaired connectors on both. I'm suspecting bad wire.

 

[acai]

Yeah I have new OEM on both and repaired connectors on both. I'm suspecting bad wire.

Do you mean in the casing of the sensor? Or a different casing.

 

[Tedward]

@acai

Can you be more specific as to how the motor behaves.
Is it retarded timing, limp mode, or runs crappy....

 

[acai]

@acai

Can you be more specific as to how the motor behaves.
Is it retarded timing, limp mode, or runs crappy....

I will try my best to describe:

I start driving after I clear the code. The engine fires up normally and sounds and runs fine initially at <20mph neighborhood speeds under 1800 rpm. After a few mins I try to pick up speed on a longer street in my neighborhood. Shortly after I hit 1800-2000 rpm on the straight and turn onto another street. Right then when I hit the gas the truck barely accelerates given the same gas as before and I hear a deep exhaust note upon giving it gas. At that point the CEL clicks on, Code 55. Driving around more it struggles to accelerate and feels like general lack of power at that point. Forget driving on the freeway or even city streets, not able to accelerate enough for that. Once I clear the code it goes back to normal until I try again. When I have it in park running on my drive way, it idles normally.

 

[NLXTACY]

Do you mean in the casing of the sensor? Or a different casing.

In the wire going to the harness/ECU

 

[Tedward]

Thanks for that description.
That's what I experienced too. When I get home, 6 days from now, I'm going replace the knock sensors and and connectors I've got on stand by.
Fingers crossed.

 

[alia176]

Simply disconnect the knock sensor wires and go for a drive. I'm curious what would happen. Also, what is code 55 in OBD-1?

I drove with a knock sensor #1, #2 code for months w/o any issues. That's when I discovered the actual sensor wire was bad between the sensor and the ECU so I replaced both of them. Admittedly, I have OBD-II so perhaps the ECU is programmed differently, I dunno.

 

[acai]

Thanks for that description.
That's what I experienced too. When I get home, 6 days from now, I'm going replace the knock sensors and and connectors I've got on stand by.
Fingers crossed.

At least we're not alone on this haha. I'll let you know how the OEM sensor goes when it shows up in a couple days.