Cool thanks, I went to AutoZone and had them do it, but since the light was not on they couldn't see anything.
They are wrong. At least the person using the scantool was.
Any time an OBDII system lights or flashes the check engine light a code is stored.
It can be a hard code that light the light or did at the time but has since gone back out OR it can be a pending code that has let the computer know there is something out of parameters but not enough or long enough to light the light yet, but it is there.
The parts stores are usually quite competent at reading but someone decided 10+ years ago that they were not going to clear codes (what stupidity that is) and it has stuck with us that they will rarely clear them for you. The cool ones will hand you the tool and say "If you push this button it will clear them and turn off the light"
A flashing light is a hard engine miss. This is most commonly one cylinder ignition misfire.
Usually a COP or Coil On Plug as they call them. Many of us just call them coils because that's what they are....Individual coils and they do happen to be right ON top of the spark plug.
You might have a wire connector off of a coil but unlikely unless someone has been under the hood lately.
You prob need one new coil. Don't let ANY garage screw you for the "950.00 tune up"!
You also may only need new rubber boots. They come on the coils.
Around 100-125k is often when misfires start becoming an issue.
You should put some new plugs in it and new rubber coil boots and all could be perfect again.
You can have a good deal of moisture buildup that gets down in the plug well with the boot and that causes misfires too.
You can also get a whole set of 8 coils on ebay for under $40! Amazing but true.
I have used 6-7 sets and never had any problems with them.
My first set went 8 years before I had one on the 10 in a 6.8 V10 start randomly misfiring.
Get a cheap scantool for yourself. Get one with test results and live monitoring.
They are online for under $20 and harbor freight has some for a little bit more.
You can get a plug in one for car that bluetooths to your phone and you read codes on a phone app.
The ultimate cheapest way for now would be to see which cylinder is misfiring and put a new or known good used coil in there.
I just put one in a 2000 today with 49K original miles on it.
It ran perfect when I bought it in lat Feb and it sat until late July. It ran perfect then too.
I started it on thursday after sitting for about a month and it was missing.
I have this issue a lot. They are fine when I get them and they sit for 2-3 months and I get a misfire.
You can also find constant misses manually without a scantool by cancelling out cylinders with it running. You get it running and have someone sit inside with foot on brake and put it in drive. If you have miss the engine will shake a little and not be as smooth as it should be.
You squeeze the release tab on one of the coils and pull the connector off one at a time.
Each time you take one off, the engine will shake and run rough ans slow down a little.
If you find one that makes little or no difference...that is the bad one.