I changed my spark plugs in my 2003 Jaguar X-Type 2.5L v6 and reset my ecm thinking it might get rid of my cel and the indicator that my cruse control is not available and both are still on and my cel will occasionally flash in very short spurts while driving. The car is running beautifully so I am hoping that the ecl is on and flashing because my ecm is running diagnostics but would love some feedback. I have only driven it for a few miles since resetting my ecm. Thanks!

Bgrizzle, a flashing check engine light IS BAD!!!!!! A flashing check engine light is saying you are in a condition where you are hurting the engine or some part associated with it (in this case, sounding like you would be hurting the cats). With this being said and before we start taking guesses, get the codes read and post them here. This will give us a starting point to what is wrong.

Why do I say "give me the codes",? Well, at this point, we could have a vacuum leak, a failing fuel injector, a bad coil, mis-gapped spark plugs, ............. Too many possibilities. Lets see if we can narrow things down a bit so you are not blowing your entire wallet on the "replace this and see" parts.

My initial gut feeling is your problem is a vacuum leak (very common with these cars). This will be evident from a P0171 and/or a P0174 code. The next most likely thing would be a failing O2 sensor. You have 4 of them, the code(s) will help narrow that choice down.

+1 to getting the codes read.

Post the actual codes and not any descriptions you may be given. Generic decode lookups can often be misleading and you will need the the 'possible causes' from the Jaguar diagnostic code lookup for accurate troubleshooting.

Graham

So I took my car to get my codes for my cel right after changing my spark plugs and noticed it was driving terribly but turns out I forgot to plug back in my mass airflow sensor. (Trials and errors of being new to car repairs I guess haha) So these codes may not be helpful because it was still not plugged back in when I got them but they were P0102, P1000, P0112 and P0354. After plugging back in my mass airflow sensor and going on a drive is when my cel was flashing. Took it to work this morning and it did not flash at any point and drove fine. I tried to take it back again after plugging back in my mass airflow sensor and resetting my ecm but I think I went too early after resetting my ecm? The reader was giving all sorts of codes that didn’t make any sense so if my cel stays on after a few days of driving I’m going to take it back and get a new read.

It sounds like you’re having someone else read the codes for you. It might be beneficial to purchase a code reader and read the codes directly at home.
You would avoid driving the car to a garage with the CEL activated (steady or flashing), and possibly causing damage. The readers are generally inexpensive. Just a suggestion.

Car is running terribly now, cel flashes when I exceed 30 mph and feels like it did when the mass airflow sensor was unplugged. Car stutters and struggles to go over 30mph, could this be because it went into limp mode? Going to take it to get the codes scanned again on my way home from work and I’ll post them here. I have a shop on my way home so I don’t need to go out of my way or anything to get my codes read. Also is my only car so I don’t have much of a choice but to use it to get to work.

Alright so on my way to work the car drove terribly, on my way home it was running the same for about 5 minutes then ran great for about 10 minutes then went back to running terribly. Still couldn't go over 30 mph. Got the codes read again and they were P0303, P0304, P0102, P0112, P0354 and P1000. Not really sure where to go from here. Might end up coughing up the $100 for a diagnostics test from Ford before I take off my intake again and make more problems. Checked all my sensors that I could see and checked my hoses for leaks with carb cleaner and don't think there is any.

Might end up coughing up the $100 for a diagnostics test from Ford

Ford? Not going to help trust me.
Look up in SEARCH the codes and it'll lead you to the fixes. Disregard p1000, just means the codes have not been fixed (changes to p1111 when fixes done and drive cycles completed).

Bgrizzle, lets break down what is happening here.

P0303: Misfire on cylinder 3
P0304: misfire on cylinder 4
P0102: MAF sensor low voltage
P0112: Intake air temp low temperature (aka, high sensor voltage)
P0354: Ignition coil on cylinder 4 malfunctioning
P1000: Generic code saying that your car has not been able to complete all the necessary testing with no error codes.

So, start off with simply ignoring the P1000 code. IT is a meaningless code and does no good. I think the P0303, P0304, and P0354 can all be summed up in a bad ignition coil on cylinder 4. So, now we are really only left with the P0102 and the P0112. Both of these are coming from the MAF sensor (it has both a flow sensor in it and it measures the air temp too). So, I would venture to guess you either damaged the plug for the MAF sensor or you some how put the plug on backwards (barring putting in a wrong part). Did you happen to try and clean the MAF sensor? If so, what did you use to clean it with? Trying to see what may have happened to the MAF sensor to cause both sides of it to go out.

Alright so should I start out by switching out cylinder 4 with another coil to see if I need to buy a new one or not? Seen that on another forum as a way to make sure the coil is bad before spending the money. But no I didn’t clean the MAF, I only have compressed air for cleaning computers and such and thought it might be a little too strong for the sensor but I’m almost positive that I plugged it in that right way and also heard a click plugging it in. Is there something in particular that I should clean it with? I’m having a friend over today that is a bit more car savvy than I so hopefully we can get that done this evening. Thank you so much for all the help though! I’ll keep you posted on what happens!

Bgrizzle, with the amount of work that it takes to get the intake on and off, if you do swap the coil, swap it with the one behind the passenger headlight. You can access that coil without having to remove intake later. That would be cylinder 2. So, cylinder 4 will be the one under the air box. As for the MAF sensor, a can of MAF sensor cleaner is all you need (like $5). Spray it down the 2 chutes, dump out. Spray down, but try to fill them up. Let set in the fluid for a few minutes. Dump. Give one last spray to flush out what ever is left. Give it a few minutes to dry out. After that, look at both sides of the plug for any bent pins and/or pins that have been pushed back. That is going to be your most likely situations barring something silly. Now, with the silly being mentioned, I would be hand over handing the wiring between cylinder 4 and the MAF sensor to see if you got a squirrel or some other critter in there. They like the X-Type insulation because it is plant protein based. So, it is "tasty to them". Raises hell with a car.

Alright I’ll grab some MAF sensor cleaner on my way home and I’ll switch out 4 and 2 coil and see what happens. Was running beautifully again this morning with no cel flashing but my cruise control no available light was off when I first started but came on when I was going over 30mph. This car is getting a kick out of confusing me a think haha

Cleaned my mass airflow sensor, swapped my 4 and 2 coils and still no change. Checked for intake and hose leaks as well and didn’t find any. My coil lines are wrapped in a plastic tubbing (?) and there was no way to check the lines without cutting them out. I guess my next step is going to be a fuel injection cleaning and replacing my fuel filter.