It's a catalytic converter and yes i can lead to problems with the engine. It is making the engine run differently than it normally should and you will see a reduction in both performance and gas mileage.
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"I'm not driving too fast...just flying too low"
Mine:
-87 ranger- broke
-03 SB Cobra vert- 2552 of 5082 Born 02/25/03
Our's:
90 7up vert - new project