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Hey hope you guys are having a good one. Ive got a 98 civic lx 5 speed. Im fresh blood to engine tuning and am kinda just jumping in the deep end here. I've just gotten everything i need (OBD1 ECU, harness adapter, chip burner) and gotten a tune loaded on the chip successfully. However everytime I crank the car it jumps up and down like its pulling a vacuum leak (its not when I swapped to the OBD2A ecu everything was smooth and the idle was low) and then the engine light comes on and the car idles at 3000rpm. I can provide furhter info and any helps appreciated

 
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Oh and i forgot to mention, the ecu came with a tune already and it had the same idling issue. Am i looking at a bad ecu?

 
Rep Power: 126

You’re either looking at a bad ECU or a bad tune.