Obd 2 302/351 How To

enyawix

Member
Dec 18, 2005
507
0
19
127.0.0.1
This is a work in progress please correct me where I am wrong. I hope people are willing to help with pictures and documentation. Many people have asked about this, but the conversation always dead ends, or someone says they did it, but will not say how. Tightening emissions standards and rising fuel prices have made this a priority for me.

You could just get a 4.6 to address emissions issues, but I personalty do not like the 4.6 because all of its power is made higher in the rpm band. I like being thrown hard into my seat. I am yet to see a 4.6 do that naturally aspirated.

A magazine did a OBD 2 coil on plug 5.0 a long time ago, but would not say how. Time to stat the parts list.

Mechanical parts?
302 or 351 engine with EFI intake
302 or 351 Camshaft Synchronizer with gear for roller cam
1994/95 K member
High Flow Catalytic Converters
351w swap headers ?
Engine swap oil pans ?

Electronic parts?
EGR valve
Coil on plug 99 to 2004 Mustang GT Wire harness
Coil on plug units
Mass air flow sensor
Coolant temp sensor
Idle air control valve
O2 sensors
Injectors

1999 4.6 Mustang computer for manual transmission

A local part store had the same part number for all 4.6 mustangs 1996 to 1999 SOHC and DOHC. Researching EGR valve and dpfe sensor setup.
 
Last edited:
  • Sponsors (?)


Pro-M makes a coil on plug system for the 5.0. However ive only see it offered when you buy it in conjunction with thier Pro-M EFI unit. Doesnt hurt to ask if they sell it by itself.

I checked out the Pro-M EFI unit. I think it could create emissions testing problems in some places, because it would be hard to make the test connector look stock.
 
The later model V8 Explorers had OBDII and a 5.0 pushrod engine. That would be the path to take.
There is a stub adapter that goes where the distributor is to turn the oil pump. There is a crankshaft position sensor to provide timing information. The rest is wiring all the components up with the proper harness.
 
  • Like
Reactions: 3 users
The later model V8 Explorers had OBDII and a 5.0 pushrod engine. That would be the path to take.
There is a stub adapter that goes where the distributor is to turn the oil pump. There is a crankshaft position sensor to provide timing information. The rest is wiring all the components up with the proper harness.


That was my first idea, but I am not sure where to get a 1998 or 1999 5.0 Explorer engine wire harness "at a good price". I can get a mustang harness off Ebay. One site made it look like the late 5.0 and early 4.6 had a simulator wire harness. The link is listed below.

https://www.ronfrancis.com/prodinfo.asp?number=MG-91E
 
Last edited:
That was my first idea, but I am not sure where to get a 1998 or 1999 5.0 Explorer engine wire harness. I can get a mustang harness off Ebay. One site made it look like the late 5.0 and early 4.6 had a simulator wire harness. The link is listed below.

https://www.ronfrancis.com/prodinfo.asp?number=MG-91E
The junkyard is always the first source in cases like this. The Mercury Mountaineer V8 is also a candidate for supplying parts.
 
The later model V8 Explorers had OBDII and a 5.0 pushrod engine. That would be the path to take.
There is a stub adapter that goes where the distributor is to turn the oil pump. There is a crankshaft position sensor to provide timing information. The rest is wiring all the components up with the proper harness.
This is undoubtedly the solution to the problem at hand!!!
 
I have ordered an Explorer Engine Wiring Harness since my last post. Also made contact with a person that posted a Obd 2 302 on a 4.6 computer. I am not using there name, because I have not asked for permission to do so.
 
Last edited:
This would be a very cool thing to have documented. One thing I wonder about is how well the computer will work with the O2 sensors and catalytic converters. I imagine that the computer is calibrated with the distance from the Explorer/Mountaineer exhaust in mind, and that it would be shorter on the Mustang. Will that affect their operation or throw false codes for catalyst efficiency? Will you be able to reuse your current 02 sensors, or do you need to change them when converting to OBD2?
 
This would be a very cool thing to have documented. One thing I wonder about is how well the computer will work with the O2 sensors and catalytic converters. I imagine that the computer is calibrated with the distance from the Explorer/Mountaineer exhaust in mind, and that it would be shorter on the Mustang. Will that affect their operation or throw false codes for catalyst efficiency? Will you be able to reuse your current 02 sensors, or do you need to change them when converting to OBD2?

I just assumed the 1999 Explorer/Mountaineer has catalytic converter o2 setup as the mustangs of the same year. Also did any of the Explorer/Mountaineer have a manual transmission?. If not want will the computer do when it thinks it is time to shift.
 
Looking at explorerforum.com the Explorer was only automatic transmission. The computer will work with a manual transmission, but strange things will happen when the computer thinks it is time to shift.

Thinking about 4.6 computer for manual transmission and Explorer engine wire harness.
 
Last edited:
With regard to the shifting issue, check out tccoa.com (thunderbird site) to see how they dealt with this in their manual transmission conversions. I believe a custom tune should be able to fix it, but it's been a long time...
 
With regard to the shifting issue, check out tccoa.com (thunderbird site) to see how they dealt with this in their manual transmission conversions. I believe a custom tune should be able to fix it, but it's been a long time...


I did not find a manual transmission conversion using the explorer or similar computer but I did find some very good wiring diagrams on tccoa.com. Now I have a good explorer computer wiring diagram. Found a 4.6 mustang computer wiring diagram on google. The explorer wire harness will not work with a 4.6 computer to get around the manual transmission issue. Will be selling the explorer engine wire harness, and building a custom harness from a 4.6 mustang and using the wiring diagrams from google. Will document as I go, so others can learn from my mistakes.
 
Last edited:
I must have missed something. Reasons for not using the 1999-2001 Explorer computer?

As I recall from my Thunderbird days, the automatic computer causes a stumble when the car has been converted to a manual transmission due to the computer thinking it is time to change gears. Their solution was to reflash the ECM to take care of it. I assume this could also be done with an explorer computer.
 
Will a 4.6L computer run a 5.0L engine? I think I would just have the Explorer computer reflashed to remove the Auto trans protocols and it should work.

Yes a 4.6L computer can run a 5.0 engine. Even a coil on plug pushrod 5.0 has been made to work. 5.0 magazine did a coil on plug pushrod 5.0, but did not document the conversion. corral.net also has a few pushrod 5.0 on 4.6 computers, but the documentation is incomplete.

If you or someone has information about flashing a Explorer computer for manual transmission that would be my first choice. Making mistakes and learning as I go.