Driving home last night when suddenly car stopped putting out power over 3k rpm. Pulled off the road, CEL was on, shut the car off then started it again. Revved the engine and below 3k sounded fine, above 3k if sounded like the car was being starved for fuel. Managed to drive it home by feathering the clutch and gas, took me forever seeing as I could'nt even go more than 10 mph. Took it to autozone this morning and here are the codes...0505, 0172, 0420, 0170. The idle problem I know about and have been trying to fix for the longest. The others are new. I'm thinking I just need to replace my cat 'cause I did hit it on something a couple of months ago and began hearing a rattle inside of it. Sound like piece of the material inside broke loose. Car is a 98 SH, 44k miles, only mod is a short ram intake. Any help will be greatly appreciated.

 

maybe you went into limp mode

 

I figured I was in limp mode but the car barely even revs. It now wont go past 2k rpm before totally spazzing out. It dies sometimes as well then wont start again unless I put my foot on the gas.

 

P0505 Idle Control System Malfunction
P0172 Fuel System Too Rich
P0420 Catalyst System Efficiency Below Threshold

i've got nothin on 0170, but everything around it has to do with O2 sensors.

I'd say you have a failing O2 sensor, and your ECU doesn't know how much fuel to put out.

This would cause the weird drivability, the normal idle, the fucked up not going over 2500 RPM, and all of the other codes.

I'd start with an O2 sensor(s), then do the cat next. Have you tried just resetting the ECU?

 

How do you reset the ecu?...Disconnect the battery?

0170 is fuel trim malfunction bank 1

 

you take out the ecu fuse in the fusebox for like 10 seconds.

 

well the poor cat efficiency is probably because its running way too rich. your cat should get really hot, especially if its running rich. it should be warm to the touch after about 30 seconds after start up. it if takes a long time to heat up or doesnt get very hot, its most likely bad. instead of throwing parts at it, maybe try diagnosis. it tends to be less expensive.

0171
Possible Cause


Fuel Pressure Regulator clogged, stuck closed
Fuel Return Pipe clogged
Fuel Injector leaking
Gasoline doesn't meet Owner's Manual spec.
Primary HO2S (Sensor 1) deteriorated
EGR System insufficient flow
EVAP Purge Control Solenoid Valve leaking, stuck opened
Valve Clearance

0505
Possible Cause


IAC valve mechanical malfunction
Fast idle thermo valve malfunction
Throttle body clogged port, improper adjustment
Intake manifold gasket leakage
Intake air hose loose, leakage
Vacuum hose leakage
ECT sensor incorrect output

 

Thanks for the help guys