cel on after intake instal!

Alright im asking this for a buddy at work! He has a 89 3/4 4x4 with th400 and a rebuilt 350 with about 3k on it so far! When it was rebuilt the original roller cam was used and its still stock bore and stroke. Anyway the only mods he has so far are 3in single exhaust with high flow cat and a 40 series flowmaster with dual tails and he just installed a k&n intake kit ! After he installed the intake the cel would come on and he said it would run a lil rough! He unhooked the batt and let it sit and now it runs fine! Today he said he took it out and got on it getting on the interstate and it felt like it "fluttered" and the light flashed then went away and was fine. I wouldnt think he would need a chip burned for such little mods but could someone else help shed some light as to whats going on? Hr plans on a rpm egr intake and tb adapter and some shorty headers too.

It has no MAF so there is another issue. TBI sucks and is so simple it is tough to diagnose for a tweener like me.

Yeah im not much on tbi at all! If its a gen 1 i prefer carb! A screwdriver and vacume gauge is all i need!

If light flashed, might be a misfire. Make sure he didnt bump any wires/sensors when he did intake. if light is on, use a paper clip and get the codes.

Ive done the paperclip trick b4 idk why i never though oh it lol. I say something to him tomarrow and about rechecking the wires/sensors.

Paperclip? Please explain.

you bend a paper clip and put it in certian spots on the diagnostic port and it will flash the cel so many times for some codes. you just gotta know what codes are what.

Or go to VatoZone and have them tell you whats wrong. I wouldn't want to risk screwing anything up.

most autoplaces won't do obdI anymore ( i know the 7 autozones i've been at won't)

OBDI is '96 and older. All '96 and newer should be OBDII.