brettdacosta

My 93 cx hatch 5-speed has the check engine light on, and I got someone to look at it. I can read the codes, but I'm not sure which ones they are. There are 2 codes : 41 and 3. He told me that they were the oxygen sensor and map sensor. I assumed the oxygen sensor was bad (throwing the code and 120,000 probably without being replaced), so I bought a universal one. The OEM one was 100 and the universal was 20 - figured I could make it work for 80 bucks. I replaced it this weekend, and I'm showing the same codes: 41 and 3. Let me know what you guys think. Why are they still showing both codes? Do I need a new map sensor? Anything will help

I also have an alternating idle where it bounces from 1000 to 1500 - very regular pattern too. I've heard that it could be the idle air control valve. What do you guys think? Is it worth replacing? Have you guys heard of this solving similar problems before? I'm not sure why it does this either. I'd really like it to stop, because 1.) it's annoying, and 2.) I bought the car for great gas mileage, and that's hurting it - which leads into my last question. What is better on gas - option 1: going up hills and at low rpm's to stay in a high gear and give more throttle (50-60%) OR option 2: downshift and run pretty high rpm's? I need all the details that you guys have on this subject too.

I'd really appreciate any help that you guys could give me. Thanks again,
Brett

kodirtysi

bump

civic_driver

replace O2 sensor and map sensor.. reset ECU...

if you still have problems, check the FITV valve on your throttle body and screw in the plunger if necessary...could be other things as well.. check to make sure you got no air in coolant.. etc.. get back to us

the universal sensor works just fine.. make sure you got the 4 wire one (i think that's what your 93 civic has)... two wires are ground, one is signal, and one is heater..

i'm about to replace my o2 sensor with universal one... all you gotta do is unscrew the old one from the exhaust, cut the wiring, wire the new one in (i suggest soldering the wires) and then cover them with heat shrink tubing (tape will fall off in those hot areas unless you use that heat protective tape).. piece of cake..

you need good map sensor in order for your car to work... i've got a 2.5bar motorola map sensor for sale... $13 shipped if you want it

good luck!

brettdacosta

Well, I'm not sure about that map sensor. I have the single wire o2 sensor, which makes me wonder if you will have the correct map sensor. If you can assure me that it will correctly fit my vehicle (93 cx hatch 5-speed) then you got it but only if you know that it will fit.

By the way, what is the FITV valve that you mentioned? And this is a really basic question, but what is and how do I reset the ECU? Sorry for the knowledge of some things and lack there of on others. I really appreciate the help. And let me know about the map sensor, and we'll work something out.

Thanks again,
Brett

92ehatch

reset ecu, pull negative battery terminal, wait 5 mins, put back on.

reset

HondaFanatic708

CEL most often indicate a problem in a circuit for a component, check for poor or loose connections, reset ECU and retest, before you go throwing $ at it though I would troubleshoot a possible electrical problem..

blcivsi

you are going to need a o2 sensor because 41 is for the heater circiut of the o2 sensor, then you should reset the ecm to see if code 3 sets again, if it does you will need a map sensor, it probably won't or not for a while. the idle needs throttle body cleaning and idle air screw adjustment(on throttle body).
good luck

HondaFanatic708

The MAP sensor code could easily cause spurratic idle. Check the MAP sensor wiring and if that checks out replace the MAP with a known good MAP sensor..