[avatar307]

Right, but how do you know if they are compatible? You have to check the part numbers on ever sensor. The O2 sensors might be compatible, they are both likely non-heated. The crankshaft and cam shaft sensors most likely are not, as they are from two different sized engines. The MAS, MAP, MAF sensors most likely will not even fit, because the engines likely use two completely different intake styles. The EGR might fit, but it's best not to mess with the EGR systems.

1994 is the year a lot of changes started happening as far as engine sensors and diagnostics. It's more likely that the sensors from a 1995, or 1996, engine would be more compatible. Then again, there are a lot of things about 1994-1996 Buicks/Olds that are completely different from other Buicks/Olds. Even within the same model year there are huge variations.

My 1995 is more compatible with 1996 parts than it is with 1995 parts. There was a huge shift mid-year 1995, and a lot of the new design for the 1996 was implimented on the 1995 to test it, as it had to be incorperated by 1996.

This is mostly due to the requirement that all cars be certified OBD-II complient by 1996. OBD-II goes beyond a standardized plug and pin out for diagnostics. It involves a huge amount of sensors and engine/powertrain diagnostics. All relating to emissions control, monitoring, and making efficent repairs of cars possible to emissions problems caused by cars needing hard to diagnose repairs.

We all think of a PVC valve as that thing that screws up the idle. In fact, it's one of the first emissions control measures. Now, it's another thing that has to be monitored. Starting in 2004, all cars must use the CAN protocol for diagnostic communication... that means no more of this 4 different adapters depending on which car you have.

Anyway, the general rule is, never mess with anything that has wires coming out of it unless you know eactly what you're doing (and have a multimeter).

Some parts will migrate between years, many parts will migrate between models of the same years, but it's very touch and go. Most sensors are related to emissions, there was a huge federally manidated emissions control systems change in 1996, manufacturers started changing in 1994. I've begun to see parts compatibility falling into these groups: 86 to 93, 94 to early-95, late-95 to early-96, 96 to 2000, 2000 to 2003, 2004.

I think one thing we can agree on is the answer to the question that was actually asked. "Thanks. Is an ECM from a 93 3.4[L] compatible with 94 3800 [3.8L]?"

Even if they use the same model and part number ECM/PCM/computer, they would be programed for two very different engines. At the very least, they use two different fuel loads, thus MOST of the sensor varibles will be different.