Awful gas mileage, loud ticking, fluctuating RPMs, poor a...

Q: Awful gas mileage, loud ticking, fluctuating RPMs, poor acceleration

asked by on March 19, 2018

2008 Chrysler Sebring convertible, 3.5l, 105k miles.

Prior to me replacing the intake manifold gasket and spark plugs, the car ran fine, but it did have a lifter tick that went away once the engine warmed up. After replacing those, the tick no longer goes away and the RPMs fluctuate slightly. I can not find a vacuum leak, I replaced the EGR valve gasket, MAP sensor and wires. It has no engine codes but the problem is still there along with god awful gas mileage, and accelerates poorly.

Any tips are highly appreciated.

My car has 105891 miles.
My car has an automatic transmission.

The RPM fluctuation, inconsistent idle, lack of acceleration, and poor fuel economy are all consistent with faults such as vacuum leaks, EGR system malfunctions, malfunctioning oxygen sensors, dirty fuel injectors, fuel pump malfunction, faulty spark plugs, a faulty mass airflow sensor, or a faulty throttle position sensor. An automotive scope can narrow the diagnostic. The root cause can be pinpointed, and the required repairs made, if you request an engine diagnostic. If you have further questions or concerns, do not hesitate to re-contact YourMechanic because we want you to make the most of your repair dollars and help you to get the best possible results.

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