I had my truck tuned with a 2 1/2 inch exhaust with y pipe into single MagnaFlow dumped now I've up graded to a full 3 inch x into an actual Nascar boom tube side exit how will this effect my tune? It's alot more open now than before has some slight hesitation and service engine light comes and goes... does it need to be re dyno d or jus checked by my tuner at idle? Thanks guys...

 

Have you pulled the code to see what it is?

 

Yes it said o2 sensor codes changed those and it still had a lean on bank 1 code or something. I jus figured since the east is opened up now I might need more fuel but changed plugs and o2s it helped but at wot it's fine jus putting around is when it sputters like a carburetor would.

 

following

i just sc my 5.3 canyon and am having these same issues. used stock maggie tune but now running 1 7/8 long tubes and 3". only spits and sputters sometimes tho.

 

Well u definatly need to have it dyno tuned with ur exhaust...my issue is I have already had it dyno tuned but it had a small exhaust on it now it's full 3 inch and really open. I think my air fuel mixtures ju d need adjusted...which is prolly ur issue too but on the dyno they can get max power for u.. does urs mainly do it at between 1500to3k rpms? At wide open throttle it is fine all the way to 6700rpms.

 

Also u have bigger tires the dyno Can adjust ur tire size shift point watever u need.

 

mine has done it literally all over the board, once at just an idle speed rolling out of the driveway and some at 3500rpm and some at 4500rpm. never at wide open tho

 

Your tune fixes tire size/shift points... Not a dyno. It's a measuring tool only.

Yes, if you made that big of a change in exhaust you will need it retuned. Do you have any gauges to monitor that thing? I'm sure your boost changed with the new exhaust too.

 

would it have dropped in boost?
no i do not have gauges yet. ill hopefully get them this week.

 

Yes, you should have lost boost pressure... But gained power, all else being the same.