2002 Mitsubishi Mirage hesitation, "bogging down"

NTYMD8R

MEMBER
2002 MITSUBISHI MIRAGE
4 CYL
FWD
MANUAL
19,200 MILES

My first time here.2002 Mitsubishi Mirage 1.8L with slight hesitation in 1st and 2nd gear. Poor acceleration all through out the powerband. Will not go faster than 70 MPH on flat surface (3000 RPM, 5th gear). After 3000 RPM (4th gear), engine boggs down at WOT and seems to actually slow. CEL came on prior to this and I checked it. EGR valve problem. Found major carbon buildup inside. Totally cleaned and removed the deposits. CEL is off now but symptoms persist. Changed plugs and wires. Symptoms still there. Did a compression check, 180, 175, 180, 175. All good and strong. Symptoms still there. Unplugged front O2 sensor, no change. What else could cause this?

2 Replies

NTYMD8R

MEMBER
2 POSTS

Oxygen sensor.
Catalytic converter.
Mass airflow sensor/Airflow meter.
Throttle position sensor.
Crankshaft position sensor.
Knock sensor.
Manifold absolute pressure sensor.
False air leakage.
**Wouldn't all of these throw a code?**

Fuel injectors dirty/sticking.
**Used a fuel injector cleaner, Codes? Can I pull them and clean them?**

EGR Valve
**Cleaned, no codes**

Fuel pressure regulator leaking or defective fuel pump.
**No problem starting or idling, no fuel smell**

Fuel contamination.
Foul/defective spark plugs.
Open spark plug wires.
Ignition coil/Coil packs defective.
**Ruled out**

Incorrect ignition timing.
**Can a timing belt loose a tooth or two and still function?**

Cap and rotor.
**Does not apply**

HELP! I'm obviously looking for the least expensive route, due to all of these possibilities it'll probably be expensive. Can someone answer the few questions I have previously asked? Codes? Timing belt?