From my perspective cheap code readers, or code readers in general are just frustrating. Ok. they give you a code to research but are not a lot of help in diagnosing whatever the problem is.
I want something which gives me definitions, like
MES, and then lets me explore the problem by seeing values and/or driving actuators. Has to be said though, without a certain depth of understanding about how these systems work most people are on a hiding to nothing and stand the risk of causing more damage to delicate electronic components. In truth I find
MES is quite enough for me and lets me do most of the stuff I want to tackle myself at home. Also, as long as you've got a device - mine's a laptop, the software is cheap enough to buy and in my opinion a bargain considering how much it lets you do. You just have to get used to the rather different description for some of the operations/results - "mixture correction learning value" or "Lamba sensor integrator"? I can make a good guess but I've never seen these descriptions anywhere else? VCDS is a whole new ball game and is such a powerful tool I can't even do half of what it's capable, some of the coding and programming ability terrifies me. For instance there's the prospect of reducing the max revs limit but having done that you can't subsequently reset it to a higher limit! However, maybe I've been saved from my ignorance because Grant, at Gendan, tells me the version of VCDS I have, and more relevantly, the interface I'm using, won't be able to do much with the new Scala. He also tells me that there are certain aspects, Electric handbrake wind back and others, which are now blocked by the new protocols. Ross Tech are apparently working on a "work around" which they hope to have ready later this year. Mind you the new car will be under warranty for the next 3 years so I'm probably better not to touch it beyond doing stuff like putting anti seize on the wheel hubs to stop the alloys seizing on. By the time the warrant expires I'll be 80 and may even have been banned from driving by then!