[cmedlin96]

hi guys, im having some trouble with my 96 gt 5 speed. i just replaced my catted h-pipe with an o/r h-pipe because my car was studdering and losing power randomly. i had a check engine light saying insufficient flow or cat below threshold (i forgot), anyway i figured my cats were clogged. after changing that out my car ran fine for about a week , then it started doing the same thing . itll run like a champ one day and then all of the sudden the idle surges , i lose power , kinda like its running rich, and the check engine comes on. i turn it off to plug my scanner in and bam , no codes . crank it back up and it runs fine. it does this almost everyday. the only thing the scanner shows is EGR monitor not ready. ive already checked for vacuum leaks, new plugs, cleaned MAF, new IAC, new EGR Valve. just recently when i turn the ignition on, the check engine light will flash rapidly, like the power is turning on and off really fast, and the fan comes on. is it a CTS ? TPS ? o2 sensor ? PCM ? i really dont want to dump any more cash untill i know what is the real source of the problem is. i know that it could be many different things wrong but im stuck at this point so any help is appreciated.

thanks,

 

[chuck192]

Ignition coil pack going bad?

Sent from AutoGuide.com Free App

 

[cmedlin96]

Ive been thinking about that too. Ill try that and see what happens.

Thanks for the response.

 

[cmedlin96]

So guys i took my car to get it diagnosed and they told me that i had a short somewhere. How am im suposed to find a short in the wiring harness with like 100 wires in it ? Im not blowing fuses either. Help !!

 

[Hood Time]

I was leaning toward electrical as well. I can already hear WMBURNS, "Check battery and alternator first. Modern cars can't run without a good charging system." Lol. But that's true.
Turn off your car. Make sure everything is off. No car chargers plugged in, etc. Then disconnect negative battery cable. Then connect test light or voltmeter between neg cable and negative battery post. Check if there's still current flowing.

 

[Hood Time]

^ That's the "see if there's a short" test.

If there's no current flow in the test above, then there isn't a short. Then you would test the battery and alternator.

If there IS current flow, then you start pulling fuses one at a time. Start at the engine fuse box and work your way to the interior fuse box. Each time you pull a fuse, check if there's still current flowing. If the current disappears, then you found the circuit with the short. Then you check the components and wiring for the short.

I had an eletrical issue not too long ago as well. Had me scratching my head, but ended up being my battery cable rubbing against my driveline. Here is the thread is you care to read... http://www.allfordmustangs.com/foru...ng-while-driving-under-unknown-influence.html

 

[cmedlin96]

Thanks alot ! I will definitly be doing this in the morning!

 

[cmedlin96]

i did what you said with the battery and i still had current flowing. i checked all the fuses and the voltage didnt change and no fuses were blown, im starting to think i have a bad ccrm, a blown fuse or relay in the ccrm, or a short going to it. is this a possibility? thanks

 

[Hood Time]

Did you pull each fuse one by one to narrow down the short as instructed?

And also make sure NOTHING is on. Like interior lights, cell phone charger, etc.
Dont forget to pull out your amplifier fuse if you have one to eliminate that.

 

[cmedlin96]

I had everything off and i pulled each fuse just like you said. I did have my subwoofer amp still plugged on the positive side of my battery . Would that cause it to still have current?

 

[cmedlin96]

Alright guys. I put new msd coil packs and ford racing wires on today and it hasnt been running rough at all. Its only been a day but i hope that was my main problem. Anyway. The other thing is , the theft light sometimes flashes and the fan comes on when i turn the ignition on, i can still crank
It but it runs like s***. It only does this randomly and i can ussually keep turning the key on and off or take it out and put it back in then it will crank normally without the flashing theft light. Im thinking the ovbious, PATS. But what would cause it to do it and then "work its way out" i guess. ? Is it my key going bad?