02chevy silverado flashing check engine light

The Check Engine light flashing is a pretty much universal sign that you have a misfire that is bad enough that a lot of raw, unburned fuel is being dumped in to the Catalytic Converter, to the point that it could be ruined if the problem is not taken care of very quickly. If that happens, you're looking at usually a few hundred dollars, on top of whatever the original problem is. It's also, a fire risk, as the CC already gets very hot normally, but even hotter if overloaded.

My truck didn't do it before we replaced the main rear seal

I would think you made to go have the code,s read.and yes it is probably misfire,but it also might be a bad sensor,Did you make sure you pluged all sensor in after you installed rear seal,may be just left catty oxigen sensor wire loose.

Does the engine seem to idle a bit rough? Another way to tell is to feel the exhuast, a constant air flow is good, but a sputtering of exhaust is a sign of a misfire. The tapping noise you have, I am not sure what that is.

I had my codes read at autozone today it said there is a misfire but someone on yahoo answers said it may be my catalytic converter but I didn't have any problems with that before could it b that?

And u said that too

You said it didnt start till after?

We checked all the plugs n yes it did not start untill after. Before it ran perfectly fine my seal was leaking so I replaced it

An engine misfire may be the fastest cause of problems for the catalytic converter. Engineers provide the check engine light with monitors to check for misfires. They program the PCM to flash the check engine light when they occur. Ignoring a flashing check engine light is an invitation to disaster. We must address a flashing check engine light immediately to avoid converter problems. The cause A misfire can destroy a catalytic converter in a matter of minutes

I took it to auto zone the codes read : a cylinder misfire detected-random cylinders Explanation: the power train control monitors the crankshaft speed and and detects a misfire condition. Probable cause: Ignition system Fault- spark plugs Ignition wires Vacuum leak Injector fault High or low fuel pressure

I'd go with a possible vacuum leak. You removed a lot to change the rear main seal and may of not connected everything up tight. Sometime moving one item will start a slight break in another seal. Have the fuel system checked for leaks. Have the ignition system checked for lose wires or bad sensors or computer module. Since you state the misfire is random, it is not at just one cylinder, but in you command module that controls the ignition. or plug firing. The knock. Do you know were it is coming from? Could it be the misfires or the crank hitting something not p;ut in correct when replacing the seal? Use a stethoscope to find the knock. It very well could be the misfiring causing the knock. Believe the codes.

Mine has flashed for 6 years, don't worry about it.

I just purchased a 02 silverado 1500hd with a 6litre.same issue!flashing check engine light. Rough idle.any ideas??new manifolds..plugs and wires.was told that the cats may be plugged up.gutted them and it still flashing.help!!lol

Your cats send messages to the computer that runs the ignition timing and fuel settings. With plugged or gutted cats, the computer is getting bad messages. Replacing the manifolds means there was either major problems, or customized work was done to the engine. Have you tried to resink the computer to the new equipment? Is everything hooked up correctly? Vacuum leaks can rase havoc, and wrong sensors also. What else was done to modify the engine? If you just bought the truck, was it an "as is" purchase, or from a dealer that you can take it back to to find the issue and repair it?

To mine has flashed for 6 years , How did you managed to get pass emissions ?

What ended up being the issue? Mine is doing the same thing. Strange tapping sound.

I have a 2004 Chevy 5.3 engine with the same problem flashing light started with my knock sensor been bad after that it started with miss fieres change sensor oxygen knock and map sensor new plugs wires but still rough idle that bad thing it goes away after a while normally does when it sits fir a while any idea

2005 5.3 with same problem. I changed plugs and wires but that didn't do much. Then i cleaned the injectors and that took the slight knocking away. When i turn on the pick up it doesn't have steady are flow out of the exhaust until it warms up. The light is random but there appear to be nothing wrong. I've owned the pick up for half a year now.

Its the crank sensor. Either its bad or its not shimmed right. Trust me i had the same issue and it can cost u $

I was riding down the road all the sudden my flash engine light came on the i barley made it home and its hard to cranck

I had the same issue with my 2013 Silverado. Flashing engine light and traction light with engine idling rough. I had recently had my oil changed a bit on the late side. The oil change shop didn’t reset the oil life indicator. It said 4% when these problems started. I reset the oil indicator. Lights went away and everything ran smoothly. Turn the key all the way without starting the engine. Press the gas pedal down three times, and turn the engine on.

To all of you gentalmen . Some free info for your Knowledge banks today. So the random misfire on not anyone same cylinders and the ticking noise your hearing is from and believe e me or Not . Take off your intake underneath are your knock sensors pull them and replace them before you do anything else everyone says it's the cats just cutt them off. NO CAUSE then your going to have 02 issues . And fuel air mixture problems . Those cats provide a back pressure also into the engine haven no restrictions alot of the time just causes more issues unless your running low 7s at the track on the weekends . Then straight piped or what ever is okay. When city driving and or short country driving need that back pressure . When the sensors go bad they dont read the knock the engine produces and cant send info to computer to make changes inside or outside sensors . CAM sensor etc. So in this change out your knock sensors .and check all your wiring. The Map sensor on the back of the motor could be done or not sealed .also Check your main harness also on top of engine has harness that goes to injectors coil pks etc. I had a truck do this last year after changing everything every sensor plugs coils etc . It ended up being a corroded ignition wire .in the harness . AMD the knock sensors ...

I had this problem on and off every few months starting around 70k miles on my 2020 Silverado. In my case the flashing light would flash for a few seconds and then stop, and then it wouldn't happen again for weeks or months. Engine never faltered or ran different when it happened. Sometimes it would blink after hard acceleration, and then stop blinking. Started to happen more often, so took it to the dealer at around 100k miles, they said was probably a bad fuel injector, the wanted me to bring it back for a couple of days for them to have overnight for a test after a cold start. Before I could get it back to them, was accelerating onto the freeway and got the blinking light with lifter failure and clattery valve noise. Pulled over immediately and had it towed to the dealer. Turned out to be a failed lifter caused by the AFM system, with a bent pushrod and a chewed up cam. Required total engine replacement for a cost of $10k+. If you get this blinking check engine light, take it to the dealer immediately. If I had documented the problem this way when it began, GM might have covered most of the cost. As it was, this is a known issue, so they knocked off about 35% of the cost, even at 105k miles.