I have an '01 PSD and an older SCM tuner. It only has 3 settings: stock, tow safe, hi perf. if i ran it on tow safe or hi perf, would my vehicle be harmed. Keep in mind, I don't have any mods. No gauges, no exhaust upgrades, no intake upgrades. Thanks.

Danny

 

Don't go any higher then tow safe.
Nut

 

get a set of guages and you can run it as high as you want. you should be fine with the tow mode without them

 

If you do any towing, I'd go back to stock. But for normal driving you should be okay with the tow safe.

 

You're pretty much playing with fire, running ANY tune other than stock, without gauges!! Personally - I'd put 'er back to stock until you get gauges - ESPECIALLY with a stock intake and exhaust!