Stupid "check engine" light

[SSJ2Gohan]

Ok ive had both of them replaced.  Either their is a 3rd one on my s14 or one of them has gone bad again.  one was replaced about a year and a half ago and another was replaced about 1 year ago.

Is there anyway to figure out which one it is before going to the dealership and buying a new one?  Buying the part doesnt piss me off but paying them to use their electronic testers to figure out whats wrong (even though im betting o2 sensor again) does irritate me since i think its a waste of money on labor for 2 minutes worth of actual work.

Any ideas?

[gh6o6]

1. remove kick panel on pasenger side to gain access to the ecu
2. unbolt the ecu from side wall phillips head or 10mm socket (i think)
3 unclip white wire GUIDE not harness.
4 rotate ecu fully around to see the back where there is a screw
5.turn key to the on position
6. turn flathead screw fully clockwise
7. wait 2 seconds and turn it back to fully counterclockwise (make sure you are looking at the light and ready to count when turning back)
8. this will show the trouble code - (The check engine light will blink to show this, for instance, blink..blink..blink......blink..blink, will be 32)
9. After you read the code, you can start the engine
Turn the bolt back to the clockwise position for at least 2 seconds(While running)
10. Turn it back to the counterclockwise position
11. Now shut the car and then start it again, this should of removed the code.

Codes:
Camshaft Position Sensor             11
Mass Air Flow Sensor                   12
Coolant Temperature Sensor         13  
Vehicle Speed Sensor                  14  
Ignition Signal Primary                  21
IACV-AAC Valve                         25  
ECM                                         31
EGR System                               32
Front O2 Sensor                         33
Knock Sensor                             34  
EGR Temp Sensor                        35  
EGRC-BPT Valve                         36
Closed Loop                               37
Intake Air Temp Sensor               41  
Throttle Position Sensor              43  
CYL 4 Misfire                             65  
CYL 3 Misfire                            66  
CYL 2 Misfire                            67  
CYL 1 Misfire                            68  
Random Misfire                         71  
TW Catylist System                   72  
Fuel Injection System                76  
Rear O2 Sensor                        77
Crank Position Sensor (OBD)        82  
A/T Diag Comm Line                   84  
Crank P/S (OBD) Cog                 95  
Coolant Temperature Sensor       98  
Park/Neutral Position Switch       103  
EGRC Solenoid/V                      105  
Inhibitor Switch                       111  
Vehicle Speed Sensor A/T         112  
A/T 1st Signal                         113
A/T 2nd Signal                        114  
A/T 3rd Signal                         115
A/T 4th Signal or TCC              116
Shift Solenoid/V A                   118
Shift Solenoid/V B                   121
Overrun Clutch S/V                 123
TOR Conv clutch SV                124
Line Pressure S/V                   125
Throttle Position Sensor A/T     126
Engine Speed Signal                127
Fluid Temp Sensor                   128
A/T Comm Line                        XX


This came from 240sx.org - simple research, and it is also easy to do
55 is an all ok code

[gh6o6]

and you cany buy an o2 sensor at any auto parts store

[Dunkee]

I've got the same problem; I just changed my front O2 sensor...it drove great for a day... <img src="http://www.zilvia.net/f/iB_html/non-cgi/emoticons/satisfied.gif" border="0" valign="absmiddle" alt=':satisfied:'> then that stupid "check engine" light turned on again &nbsp; <img src="http://www.zilvia.net/f/iB_html/non-cgi/emoticons/mad.gif" border="0" valign="absmiddle" alt=':angry:'> It's really frustrating cause I just bought the car. Anywayz, I'm going to Nissan today to see what they say.

[Broadwayblues]

Is this the same procedure for the S13? Car is out in the parking lot, can't get to it right now and this is killing me! I have to know!

Thanks!

[gh6o6]

dunkee dont go itll be expensive
s13 is a little different with different codes goto
<a href="www.240sx.org" target='_blank'>www.240sx.org</a> then faq then ecu resetting

[SSJ2Gohan]

Ok im missing somehting on getting the thing out. &nbsp;I took off the kickpanel and saw the ecu and that wire harness with the clip. &nbsp;I detached that and unscrewed the screw (on the bottom) and the screw that was attached to the bracket near the top.

It wont budge though. &nbsp;I think there is a bolt on the back that looks like a screw from the other side into a bolt. Does this need removed also? &nbsp;If not what am i missing cause that sucker will not come out.

[SSJ2Gohan]

Any ideas?

[Dunkee]

</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote (gh6o6 @ April 16 2002,6:37)</td></tr><tr><td id="QUOTE">dunkee dont go itll be expensive
s13 is a little different with different codes goto
<a href="www.240sx.org" target='_blank'>www.240sx.org</a> then faq then ecu resetting</td></tr></table><span id='postcolor'>
I actually tried getting the codes myself through the ECU, but it didn't work. I know I did it right...I did it w/ my friend and he's an airplane mechanic so I know its a problem w/ the ECU. The dealership I bought it from replaced it w/ an ECU they got out of a junkyard (the damn red LED on it is even missing). Anywayz, I turned the "mode screw" like I was supposed to and the "check engine" light didn't blink. So the only way I can get the codes is through one of those scan tools...75 bucks down the drain <img src="http://www.zilvia.net/f/iB_html/non-cgi/emoticons/sad.gif" border="0" valign="absmiddle" alt=':('>

[Dunkee]

</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote (SSJ2Gohan @ April 16 2002,6:58)</td></tr><tr><td id="QUOTE">Ok im missing somehting on getting the thing out. I took off the kickpanel and saw the ecu and that wire harness with the clip. I detached that and unscrewed the screw (on the bottom) and the screw that was attached to the bracket near the top.

It wont budge though. I think there is a bolt on the back that looks like a screw from the other side into a bolt. Does this need removed also? If not what am i missing cause that sucker will not come out.</td></tr></table><span id='postcolor'>
I had the same problem too when I took mine out; I've got a 96 so I don't know if it's the same but there was a small plastic "plug" (I don't know what it's called) above the ECU. You just have to force it out but you have to be careful not to brake that plastic plug. I hope this helps.

[SSJ2Gohan]

Ok i took the flathead screw bit and wrenched my hand back there and found the hole without removing the ecu since I couldnt get it out. &nbsp;Anyways the error code said 55. &nbsp;I looked above and it looks like that means good to go. &nbsp;Any ideas why my check engine light would be on and then the error code was a 55? &nbsp;Its not on anymore since I cleared the ecu and Ill wait and see if it comes on after driving around tomorrow. &nbsp;Any ideas in the meantime?