2001 Tahoe Service Engine Light Flashing

[dawgfan83]

Guys, sorry if this is repetitive, but I've attempted to read through all the posts hoping to find the solution and so far I haven't. So, here goes my story.

First of all: 2001 Tahoe, 5.3, 190K miles, new water pump, fuel pump, fuel filter.

Haven't been driving the Tahoe much recently because of my commute, but I do drive it on occasion for longer trips. The last couple times I have driven the Tahoe, once I reach about 65mph highway speeds, the SES light will flash 10-15 times. I do not notice any loss of power, no rough running, no rough idle. RPM's remain steady with no fluctuation and nothing else seems out of the ordinary. My SES does stay lit and last time I checked, the GM dealer said I had a knock sensor that needed to be replaced.

I consider myself somewhat mechanically inclined so I'd like to investigate on my own.

Any suggestions or advice on where to start, common problems, check this first, etc., would be greatly appreciated. Thanks so much for your time and help with this matter.

 

[El Capitan]

Typically when a CEL is flashing it means pull over and have it towed to a dealer. How ever what I would do is go to autozone and have them scan it and get the print out of the code/codes and see what they may be.

 

[John03Z71]

I had a similar problem with a flashing check engine light except my engine was misfiring. When scanned it gave a P0300 code (random or multiple misfires). When the problem first started I barely noticed any change in performance and it was very infrequent. Over time it started flashing more often and I began really noticing the misfires. I spent a lot of time researching possible causes since it is such a generic code and there are many possible culprits. I replaced my plugs and wires last year (NGK plugs) so I didn't think they were the problem. However, I went ahead and replaced them a few days ago with AC Delcos and so far so good.

Interesting story, when I ordered the wires online last year I remember ordering AC Delco brand and they came in an AC Delco box. I must not have paid close attention to the actual wires when I installed them back then because when I switched them out the other night I noticed they are knock offs... "AC Dalce" brand! Identical font, logos, words, lettering, everything. Unbelievable. Wish I remember where I ordered from. Check out the attached pic.

Sorry to rant but just saying if you scan it and get a P0300 code, swapping out your plugs and wires with genuine AC Delcos is where I would start.