I noticed something surprising last night while under the hood. I ran some of that Seafoam Engine Cleaner through a vacuum line and after letting it sit for five minutes as the instructions suggest, I restarted it to watch it smoke for a couple of minutes. It stunk but it not too much smoke out of the rear. I was kind of disappointed actually. Anyway, back on topic, I noticed when I revved it up and let off, I would get a little puff of smoke coming out from the turbo. I suspect its at the exhaust manifold as that was replaced last year while I was deployed. The shop that did it didn't do the best work.

I pulled the codes and I got a 1-1-3 (Fuel trim (lambda control) too lean or rich). The FAQ indicates the cause of fault is: "Mixture incorrect; O2S wiring fault". Could this have been caused by my exhaust leak? I'm going to try to hook up a calibrated boost gauge this weekend and see how much boost I'm getting. It doesn't feel as strong as it used to under full throttle.

On a side note, my turbo has begun passing a little bit of oil too. Probably one quart every 3K or so. I guess its still got some life in it but it sure does make things messy downstream. I don't know if this has any bearing on the above problem or not. Thanks for any input or experiences.
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92 745T 126K; 83 242Ti 188K - Brick on blocks for now.