88 xj wont pass emissions high CO reding

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05-04-2015, 08:35 AM

88xj4.0

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Model: Cherokee

88 xj wont pass emissions high CO reding

Hi im having a hard time passing emissions. I have a 1988 cherokee 4.0 with 261,000 miles. Took it for the test the other day and i failed. The paper says i have a high CO reading at high RPMs and i have a high reading for HC and CO at low RPMs. The jeep seems to run pretty good just changed oil.anyone know what it coild be or how to get it to pass? Ill attach a pic of the test thanks.

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05-04-2015, 08:57 AM

cruiser54

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Year: 1990

Model: Cherokee (XJ)

Engine: 4.0

Some history?

Last time it had plugs, wires, cap and rotor?

Ever replaced the O2 sensor?

Intake manifold bolts loosened up?

Ever done any of my Tips in the Pink Link below? 1 through 5 are quite important on an 88.