What are your plans with the car? If you don't plan on modding it then yes go ahead and get retuned. If you want some more power do your homework on here, get a few easy power adders, then get retuned.

 

Get another tune. Simply because:

1) Its 5-6 years old, technology and knowledge on tuning these cars have changed.
2) You had added new parts and therefore some minor tweaks are needed.
3) You should have it tuned to someone you know is reliable, knowledgeable and experienced, and not just by your previous tuner. Evos by nature are a little bit more maintenance heavy than other cars, however this is due to the increased performance you get.

And as for the AFR gauge, Its good to have one so you can monitor how lean or rich your engine is. Its not absolutely necessary to have one, but it is highly recommended if you are running modifications on your Evo. Have a $200 Wideband Gauge as an "Early Warning System" to save from a potential $2-4k repair bill is worth it in my opinion.

 

I didn't see anyone answer the question - Does a tuned car get out of tune overtime (assuming no parts are changed) ? I would guess no because its a programmed chart. However, my stock evo, I noted that evrytime I reset the ECU by removing the battery terminal, seems to run better. So, I guess, as a follow up question, does the ECU learns itself and set its values based on its input

 

depends what else you plan to put on your car. eg. exhaust , turbo or whatever, maybe wait til you get more parts and tune it at once ! tuning aint cheap.. atleast where im from (decent tuner in AUS would b looking ATLEAST $500).. although i dunno if it would b cheaper if the cars already been tuned and its just tweaked ??

 

I would always get a re-tune if you change any part on the car performance wise. Also if your af ratios are weird at wot or cruise trims

 

I would install a wideband for peace of mind and cheap insurance. I know in my car that with running meth I always pay attention to my afr's at wot, you never know if the pump craps out and you lean out. Also I know that my afr's do lean out a tiny bit in this cold winter weather because of that nice cold dense air. Also if you do decide to get retuned it woundn't hurt to throw in some new plugs for some good spark.

 

retune

 

+ gauges