Georgia Mike
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- Jul 23, 2012
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1999 Chevy Suburban K1500, 5.7 Vortec. Heads were replaced 2 years ago by the PO. I was told he replaced the intake gaskets at that same point. Newer plugs/wires/cap/rotor. When I first bought it, it had a pretty bad stumble (more like a "bucking") from time to time when the accelerator pedal was released. After a little work it was discovered that he had ALL of the injector spider legs on the wrong cylinders. After that it ran much better but still had two reoccurring codes: One was for the O2 sensors, so I replaced all four and that code has gone away for good.
Now I still have the one code left and it has me stumped. It's "P0020", and from what I've read on internet searches:
Possible causes
- Dirty Oil
- Faulty variable valve timing (VVT)
- Variable Valve Timing (VVT) circuit is open or shorted
- Oil Control Valve (OCV) circuit is open or shorted
- Faulty oil control valve (OCV)
- Damaged Engine Control Module (ECM)
One thing I should mention is that I have a Hypertech Power Programmer. Whether the program is in the PCM or not, the code will crop up. Sometimes the engine feels like it has a very slight miss, other times I don't notice anything and look down to see the CEL has come on at some point. One point of note is that I once went on a weekend trip and drove it over 700 miles of mostly highway driving over the course of 3 days and the CEL never came on; when I got home and started doing the daily driving routine it came back on within a couple of days.
I have a scan tool, but the Hypertech unit has its own reader as well and that's where I got the P0020 code. I have yet to go without the program installed long enough to set the CEL so that I can check it with my dedicated scan tool to see if it gives the same code, but something seems amiss with this code description being as how the 5.7 has no VVT or OCV circuits to have a fault. So that leaves the last thing on the list; faulty ECM.
Anyone have any suggestions?
Sorry for this long-winded post, but I just wanted to get all of the info that I could think of out there in the hopes that someone else may have had a similar experience, and see what their solution was.
Now I still have the one code left and it has me stumped. It's "P0020", and from what I've read on internet searches:
Possible causes
- Dirty Oil
- Faulty variable valve timing (VVT)
- Variable Valve Timing (VVT) circuit is open or shorted
- Oil Control Valve (OCV) circuit is open or shorted
- Faulty oil control valve (OCV)
- Damaged Engine Control Module (ECM)
One thing I should mention is that I have a Hypertech Power Programmer. Whether the program is in the PCM or not, the code will crop up. Sometimes the engine feels like it has a very slight miss, other times I don't notice anything and look down to see the CEL has come on at some point. One point of note is that I once went on a weekend trip and drove it over 700 miles of mostly highway driving over the course of 3 days and the CEL never came on; when I got home and started doing the daily driving routine it came back on within a couple of days.
I have a scan tool, but the Hypertech unit has its own reader as well and that's where I got the P0020 code. I have yet to go without the program installed long enough to set the CEL so that I can check it with my dedicated scan tool to see if it gives the same code, but something seems amiss with this code description being as how the 5.7 has no VVT or OCV circuits to have a fault. So that leaves the last thing on the list; faulty ECM.
Anyone have any suggestions?
Sorry for this long-winded post, but I just wanted to get all of the info that I could think of out there in the hopes that someone else may have had a similar experience, and see what their solution was.
