I recently bought a 1993 Lexus SC400. During these years, Lexus unknowingly built their ECUs with capacitors that wouldn't hold up very well over time. As such, I needed to replace all the capacitors in my ECU as a preventative measure against serious corrosion in the future.
This soldering job is not an easy one, and even though I recently started soldering, I needed to bring it to a professional. I purchased the correct capacitors for my vehicle and brought them into the shop, along with my ECU (low-ESR type if you're another early-90s Lexus owner...use a search engine and look up "all my crazy lexus issues...solved!").
I asked to pay extra for same-day service, and he replaced my capacitors in under an hour, even though it was the end of the day and he finished up a few minutes after closing time.
The difference is remarkable. My gear shifts are smoother. 0-30 is noticeably faster. Two annoying sounds have ceased. I'm sure my gas mileage has improved, but it'll take a few days to confirm.
I couldn't be happier with my experience with Computer Doctor BG and I strongly recommend taking any serious soldering projects or skilled repairs here!