98 Mustang GT 4.6L Cutting out when Driving...

[skuzma83]

Howdy folks!

Just got a 98 Mustang GT 4.6L 5 Speed. It's not my first Mustang but it's my 1rst Real Mustang! I'm tickled pink at the moment. I am in love and can't wait to explore the endless possibilities! Anyways I am having an issue. I checked the car out pretty good I thought. Checked Oil Dipstick, Checked Oil Cap, Coolant Level and Fluid Color plus all the other nit picky stuff. I stopped to fuel it up. Started the car up and it ran fine for a second then died. I started it again and same result. I tried again and revved before pulling out, ALL GOOD.

Anyhow, I drove 100+ Miles in Rainy/Slushy Conditions and when I got closer to home there were puddles. I did my best to avoid them. Closer towards home it started cutting out like misfire conditions. I managed to limp it home. I ran it the other day and it was fine for a few minutes then started the misfire like symptoms again. I decided to replace the Positive Battery terminal because the old one looked like shit. I decided to go for a ride and it ran fine! A little into the ride it started acting up again but mildly then disappeared. I'm stumped.

PO CODES: PO141, PO155, P1152...

My Mods as observed: K&N Air Intake, CAT Delete 3 Inch Dual Exhaust, 8MM Wires, NGK Plugs, Steeda Short Throw Shift Kit, Newer Clutch "Stiff", Stock Coils...

Other Observations: Blueish Gray Smoke after startup then disappears, O2 Sensors Rears Unplugged and Hanging. Front O2 appears to be plugged in...

Any insight would be appreciated.

My future plan is to install a set of PI Heads of a 01 and up Police Crown Vic, Install new PI Intake, Stage 1 Comp Cams, 24LB Injectors, 75mm Throttlebody and Intake Combo... Might grab a SCT Tuner to run unless its finicky! I plan on Porting Heads, Changing Springs, Maybe +1 Valves. Dunno what kind of HP to see but im already excited.

[cwh19]

Did you buy this from a dealer?

[skuzma83]

No. Bought from a private seller in Erie. Hoping you don't have bad news by that reply lol...

[Ares]

Howdy folks!

Just got a 98 Mustang GT 4.6L 5 Speed. It's not my first Mustang but it's my 1rst Real Mustang! I'm tickled pink at the moment. I am in love and can't wait to explore the endless possibilities! Anyways I am having an issue. I checked the car out pretty good I thought. Checked Oil Dipstick, Checked Oil Cap, Coolant Level and Fluid Color plus all the other nit picky stuff. I stopped to fuel it up. Started the car up and it ran fine for a second then died. I started it again and same result. I tried again and revved before pulling out, ALL GOOD.

Anyhow, I drove 100+ Miles in Rainy/Slushy Conditions and when I got closer to home there were puddles. I did my best to avoid them. Closer towards home it started cutting out like misfire conditions. I managed to limp it home. I ran it the other day and it was fine for a few minutes then started the misfire like symptoms again. I decided to replace the Positive Battery terminal because the old one looked like shit. I decided to go for a ride and it ran fine! A little into the ride it started acting up again but mildly then disappeared. I'm stumped.

PO CODES: PO141, PO155, P1152...

My Mods as observed: K&N Air Intake, CAT Delete 3 Inch Dual Exhaust, 8MM Wires, NGK Plugs, Steeda Short Throw Shift Kit, Newer Clutch "Stiff", Stock Coils...

Other Observations: Blueish Gray Smoke after startup then disappears, O2 Sensors Rears Unplugged and Hanging. Front O2 appears to be plugged in...

Any insight would be appreciated.

My future plan is to install a set of PI Heads of a 01 and up Police Crown Vic, Install new PI Intake, Stage 1 Comp Cams, 24LB Injectors, 75mm Throttlebody and Intake Combo... Might grab a SCT Tuner to run unless its finicky! I plan on Porting Heads, Changing Springs, Maybe +1 Valves. Dunno what kind of HP to see but im already excited.

P0141 Downstream Heated Oxygen Sensor Heater circuit fault - Bank No. 1 (expected since you said they are unplugged because no cats)
P0155 Upstream Heated Oxygen Sensor circuit fault - Bank No. 2 (bad sensor or bad wire/connection)
P1152 Lack of Upstream Heated Oxygen Sensor Switch Sensor Indicates Rich Bank 2

[skuzma83]

Both fronts are plugged in. Got under there today. I decided to clean PCV, MAF, Throttle Body, Some Connections, and changed the fuel filter. Fuel filter was brownish black when it came out but no obstructions... Throttle Body had Black garbage coming out. Cleaned as best as I could. It was running fine so far. I run nothing but 93 in it. Rear O2 isn't plugged in and is exposed to water... Kinda just hanging...

[skuzma83]

UPDATE: Car ran fine for a little bit. Started its usual crap. Now Im getting PO136, PO141, PO155, P1152, P1150. Im aware of what the codes mean but obviously its not happy for whatever reason. I'm starting to wonder if he ever had it flashed at all when he added the mods or maybe even something more sinister. I also noticed that if I shut the car off then turn it back on it smooths back out. Wondering what the hell at this point. I hate OBD2. Awesome for some things, shitty for others... I don't know if anyone ever expirenced these issues? If so let me know. I hope to sell my 07 Mustang GT parts to grab a SCT Tuner...

[cwh19]

Rear 02 sensors don't do anything expect tell the computer if the cats are working. They have no influence on the cars ability to meter airflow. The upstreams, however, are incredibly important to a MAF car.

Replace the bank 2 02 that the code suggested and go from there. It wouldn't be a bad idea to just do both upstreams while you're there.

If the 02 has been bad for a while, the closed loop fueling could have made the spark plugs shit. They are cheap and easy to change, so I'd recommend those as well.

[skuzma83]

Thanks will do as soon as I get back from my hitch... I knew the codes and read. Changing the upstreams was something I was gunna try but its weather permitting for me and what side of the bed I wake up on... I pulled a plug and was thinking of the same thing. I guess it comes down to I was hesitant to do it. Oh well. Hoping that irons out the issue. In the meantime im gunna postwhore my 07 GT Stuff on Craigslist and Pennswoods to try to raise funds for a programmer... Thanks for the reply. I cant believe Ford Mustang had 6 Cats and 4 Oxys... That's ridiculous.

[cwh19]

No problem, hopefully it works out.