EEC auto, manual differences "?"

[Joe62Tampa]

I have the Scorpio shop manual for the '88 but not for the '89. The '88 I have is an automatic and the '89 is a manual and each has a different computer. The key difference I see visually between the two is that the '88 has an EGR system with 1 O2 sensor and the '89 does not have an EGR system with 2 O2 sensors.

I may need to plug the '89 EEC into the '88.
The '88 HEGO signal is pin 29.

Does anybody have the HEGO pin outs for the HEGO for the '89?
(I'm not concerned if the 2nd is in another pin location and it's not used on the '88.)

I searched the forums and the closest I came to is "this" post:

viewtopic.php?f=29&t=10310&hilit=t9+computer

But there's nothing definitive in there other than "go ahead and plug it in".

Here is the pin out for the '88.
https://www.dropbox.com/s/m1titnoezj4tm ... s.pdf?dl=0

[DPDISXR4Ti]

The difference is mostly with the '89 5-speed cars which, as you have noted, have an O2 sensor in each exhaust manifold. The A4LD cars all have one O2 sensor centrally located downstream after the "Y".

The PCM's for the Automatic cars should all be swap-able year-to-year as the pin-out is the same. I've read reports that the early ones (from the 1987 cars), are a little sluggish and improvements were seen upgrading to '88/9 computers.

FWIW, on my T-9 converted Scorpio I'm running an A4LD computer since I'm still running the single O2 sensor. It works fine.

[blugg]

always seemed odd to have 2 O2 sensors on a manual an 1 on a auto.....an those autos that been converted to manuals the single o2 has been fine.

in other news the same 2,9 overseas used dual VAMs on the intake just after the air box......but NA models, none of that extra fluff

[brokencase]

Don't the manual trans cars also have an air pump?

[DPDISXR4Ti]

Don't the manual trans cars also have an air pump?

No. My parts car is a factory original T-9 and no air pump.

[Joe62Tampa]

I've been out of commission over the past week or so. With that... Thanks for the feedback. I gave the manual EEC a try -- low hanging fruit. No (positive) affect on the running state of the '88.