[79StangPace]

Guys, Whomever had my car before me gutted the cats. I'm having a problem that when ever I go past half throttle the car misses. As long as I drive it like papa and ease the throttle its ok. Can gutted cats cause this problem? O2's?

Since my last post (a cry for help!) it has been in two different shops.
Ford changed the computer, two harnesses, fuses, coils, radio something resistors, plugs, wires, and told me my new tires were below standard. OMG
They then told me to put some new cats on it that mine were gutted and the car would not run right until I replace. They also said for the car to run right it had to have the stock air box on it instead of my BBK CAI.

Second shop said my fuel pump wasn't supplying enough pressure so they changed it with a Ford Pump instead of my napa pump that I installed. Drove it one day after and was fine, now it's shit again.

Hell with shops. I'm gonna fix it no matter what, got to much money in it now. So all info and help is greatly appreciated.

[97stanggt]

hmm i had this problem was when i gutted my cats i dinked a front O2 if u can get a live feed scanner i got my actron that shows me real time values for 140 off ebay. see if 02s are messed up if so on the net you can find em for 36 bucks to your door. and if u got a check engine light for rear 02s get americanmuscle 02 sims, now also if u have a known good MAF ;> try replacing that it could be the problem also, other then that right now i can think of anything else maybe get some MAF cleaner and clean it.....


oh and timing is good? no bent valves? good compression? other things to check


i run all 4 gutted cats 02 sims and no problems also have BBK style fenderwell CAI

[HMUSN]

it's probably the rear 02's going off because of the cats missing..

[79StangPace]

Thanks man, I will try cleaning the MAF and report back. I have no CEL, and think timing is good. Good compression. When the car is in park it idles perfect and you can rev up no problem, no misses and sounds great (I should have mentioned that in my previous post). But when in Drive Past half throttle it misses.

[97stanggt]

10-4 maybe u said the pump was replaced how bout the filter? and umm ive had a dealership screw up the wires on my 93 mark viii a long time ago make sure they didnt do that.... u can find the schematic somewhere on the net on which plug wire goes to which coil prong and which cylinder. and does the MIL light even light up anytime? could be burnt out ied have codes read ;>

[79StangPace]

Cleaned the MAF with CRC, checked the wiring order and still same problem. The fuel Filter was changed recently. I know the CEL works cause it came on before the last round in the shop.
What happens if I unplug the upstream O2's for a test drive besides the CEL coming on?
Is this like the MAF? If you unplug and it runs better its gotta be a faulty part?
Can a fuel pressure regulator go bad?

A list of parts that have been changed recently.
MAF, coils, plugs, wires, Radio something resistors, 2 harnesses, fuel pump, TPS, IAC, Computer, Fuel Filter, Camshaft Sensor, Intake.

[97stanggt]

ok how bout CPS and umm could the injectors be gummed up? if you want to try new injectors when i get my 5.4 in hopefully by the end of month ill sell ya my good stock ones for 35 bucks shipped ;> should be plenty clean get fuel treatment every 3-5 fill ups.

all injector harnesses attached good and tight? coil pack harnesses tight? the radio resistors are probly the coil pack resistors... MAF connection tight.... no air leaks after MAF? no invisibly broken vaccume lines? i had 3 breaks in mine couldnt tell they were there till i just replaced them all for the hell of it and looked real close with old ones out. does have 19lb injectors correct didnt happen to have a blower on it and took it off to sell and had 24 or so lbs on it?

[97stanggt]

ied seriously just either replace front 02s for the hell of it and good maintenance granted its throwing more parts but they could be due anyways

[79StangPace]

I agree on the good maintenance, I will get the O2's and will also purchase those sims from americanmuscle for the downstream. Will check for Vacuum leaks and harness connections tommorrow. When you complete your 5.4 swap I will definetly take those injectors off your hands. Thanks for the hook up.

[79StangPace]

Ok, pulled some codes today, but CEL never came on and I stayed in the throttle with it missing trying for the CEL..WTH?
P0353
P1270
P=451

[97stanggt]

Water, ice, mud and snow causing wheel slippage.
Excessive engine rpm in NEUTRAL.
Vehicle driven at high rate of speed.
Ford: Engine RPM or Vehicle Speed Limiter Reached

for the 1270

what it needs to trip code
Vapor pressure sensor output changes extremely under these
conditions:

Vapor pressure sensor output changes often while vehicle
speed is 0 km/h (0 mph) and the engine is idling 5 to 10 seconds
(2 trip detection logic)

Vapor pressure sensor output is stuck 5 minutes (2 trip detection
logic)


usualy causes

Open or short in vapor pressure sensor circuit

Vapor pressure sensor

ECM
this is for 451

your 353 is a coil problem of some sort....

[79StangPace]

1270 - Me revving motor in Park possible not looking at tach

451 - just changed Fuel pressure regulator, could this code be from that? Was I supposed to do anything besides plug and play?

353 - Is this just detecting a misfire or are my new coils are crap again? Hey which bank is this for?

[97stanggt]

the 353 can be caused by bad coil...which brand new can be bad..... loose coil connection or bad block ground strap connection

[97stanggt]

2ndary circuit i beleive is bank 2 which is drivers side? might be wrong but i think thats right... all you need is a 8mm i beleive swap 1 coil for the other on the sides see if code changes to 1st ckt

[79StangPace]

cool, will swap tommorrow and test drive again.

[97stanggt]

and if you want to try new... 46 or so bucks at advanced auto thats what i run on mine no problems ;>

[97stanggt]

throw me a PM so i can remember your name for the injectors my project just got moved back a lil more had ordered rods thru mustang depot called today to find out where they were only to get told their on back order for 2 to 3 weeks so cancelled order now ordering some for 26 bucks more off ebay

[79StangPace]

OK, installed the O2 simulators on the downstream, installed new O2's upstream, replaced the ground from bat to block and strap from block to body with larger wire. I also swapped the coils, inspected connections and took it for a test drive.. Same code guys.
P0353 and new code P1000

What is my next step of analysis?

[97stanggt]

DTC P1000 is an indication that the vehicle needs to be driven for a period so that the vehicle can learn certain operating characteristics

[97stanggt]

and with its 353 its gota be coils/plugs/wires on that side...or connections...possibly ecm at worst