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Mike O.
Mike O., Master Technician
Category: Nissan
Satisfied Customers: 427
Experience:  18 years with Nissan/Infiniti dealerships
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98 Nissan Frontier: cab..fuel pump,throttle position sensor

Customer Question

'98 Nissan Frontier 2.4 2wheel drive pickup single cab. What causes the motor at a constant speed to lope (motor goes up and down) Done replaced ,fuel pump,throttle position sensor,the whole distibutor, and had a diagnostic test done which found nothing.but the motor still lopes.Can you help me
Submitted: 7 years ago.
Category: Nissan
Expert:  Mike O. replied 7 years ago.

Hi my name's Mike thanks for the question!

Well a common problem for those trucks is the egr ports on the intake manifold get clogged and can cause drivability concerns not to mention it might not pass a smog test. If you remove the port plugs and clean out the passages that usually helps.

Customer: replied 7 years ago.
No Did not help, Motor still lopes(up and down)Replaced crank sensor also nothing is working what is wrong with this truck
Expert:  Mike O. replied 7 years ago.
have you checked the IAC/AAC valve yet?