Background: 1997 with 4.0L, it has always ran poorly for the year I have had it, I cleaned the MAF sensor and replaced the IAC about a month or so ago and that helped a little, but it still isn't running very well. also in the year I have had it I have never had a CEL...
I just got my scan tool today and I used it on my truck and got the following codes:
Stored codes:
P1506 IAC overspeed error
P1443 EVAP emission control system control valve
P0153 O2 sensor circuit, slow response bank 2 sensor 1
P1151 lack of H02S21 switch, sens indicates lean
P0300 Random/multiple cylinder misfire detected
P0171 System too lean bank 1
Pending codes:
P0304and 5 and 6 misfire cylinders 4,5,6
And it also said MIL status: on, but there is no CEL? so does that mean my CEL doesnt work or maybe these codes are just old ones stored in it still that have never been cleared? Since I replaced the IAC shouldnt that code have gone away? I am not an expert and would appreciate any help, Thanks -Cole

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Rides:
1997 Ford Ranger XLT 4.0L V6
1984 Yamaha YTM200E Tri-Moto
In Progress:
1971/1972? Rupp Roadster 2

If you can clear the codes, try clearing them and see if any come back within a week. If so, then your CEL bulb is probably blown or something is up in it's circuitry.

I cleared the codes and havent driven it much but I did get 2 codes again and in the live data I noticed that the fuelsys1 says cl fault and the o2 sensors all have 0 volts, does that mean that the o2 sensors are bad/ shorted out somewhere?

Live Data
DTC_CNT 2
FUELSYS1 CL_Fault
FUELSYS2 N/A
LOAD_PCT(%) 43.5
ETC(¡£F) 169
SHRTFT1(%) -100.0
LONGFT1(%) -100.0
SHRTFT2(%) -100.0
LONGFT2(%) -100.0
RPM(/min) 918
VSS(mph) 0
SPARKADV(¡£) 15
IAT(¡£F) 37
MAF(lb/min) 0.786
TP(%) 19.6
O2S B1S----B2S----
O2B1S1(V) 0.000
SHRTFTB1S1(%) -100
O2B1S2(V) 0.000
SHRTFTB1S2(%) -100
O2B2S1(V) 0.000
SHRTFTB2S1(%) -100
OBD OBD2

Stored Codes
P1152 Lack Of HO2S21 Switch - Sens Indicates Rich
P0171 System Too Lean Bank 1

__________________
Rides:
1997 Ford Ranger XLT 4.0L V6
1984 Yamaha YTM200E Tri-Moto
In Progress:
1971/1972? Rupp Roadster 2

The bulb is just bad.

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20O3 extended cab, 2wd, silver, 3.0, toyo spectrum tires, 10,000k HID's, 8' in bazooka tube, and UWS toolbox

that's what I figured, but I'm wondering about the codes I'm getting

__________________
Rides:
1997 Ford Ranger XLT 4.0L V6
1984 Yamaha YTM200E Tri-Moto
In Progress:
1971/1972? Rupp Roadster 2

Your guess is as good as mine. I'm clueless. Have you ruled out that your computer isn't just going nutts? I mean yes it is riding rough, but it could be your computer is fried. Have you been going through a lot of water.

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20O3 extended cab, 2wd, silver, 3.0, toyo spectrum tires, 10,000k HID's, 8' in bazooka tube, and UWS toolbox

how would I check if the computer is bad? I havent been going through water

__________________
Rides:
1997 Ford Ranger XLT 4.0L V6
1984 Yamaha YTM200E Tri-Moto
In Progress:
1971/1972? Rupp Roadster 2

If the O2 sensors are bad, your PCM is going to have a really hard time determining what's truly rich or lean. Also, when's the last time you changed your plugs and wires?

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2003 Edge 4x4 Sonic Blue 4.0 SOHC, Auto, 4.10 LSD, 4-door Supercab

well i've put on probably 12,000 miles since i've owned it and havent changed plugs or wires. So I dont know how long ago they were changed

__________________
Rides:
1997 Ford Ranger XLT 4.0L V6
1984 Yamaha YTM200E Tri-Moto
In Progress:
1971/1972? Rupp Roadster 2