After 250-300 miles after each 02 replacement( last time with Denso) my car starts missing,stalling, etc once it comes up to normal engine temp. Had code 43 the last two times. When it came on Wednesday, I cleared the code because it also had code 6(wire issue to the temp sensor). Yesterday and today I had the same issues but I am not getting a code. I have a oil leak which is getting on the 02 plug/connector. Could this be causing my problems? What should I check? What causes an 02 sensor to malfunction?

 

If you use a Denso, then check the connection for cleanliness and the plug is in tight. Make sure the wires is not touching the heat shield and burn the insulator. Code 43 is also related to your fuel system.

 

If you have replaced the O2 sensor 3 times and you are still getting the same code, I would say you are ether having a fuel supply issue or a wiring issue.

What do your spark plugs look like?
What is your current MPG?
Do you know if the fuel filter has ever been replaced?

 

Thanks. Think I will take off the O2 sensor and clean the connector as best as I can and also use carb cleaner on the sensor and see what happens. Ghostaccord, fuel filter, cap, rotor button, plug wires and valve cover gasket were changed prior to the first O2 sensor. If it is a gas issue, why would it seem ok for 250-300 miles after O2 replacement? Thanks!

 

What do your spark plugs look like? They are a very good indicator of what is going on in the combustion chamber.

 

I will check the plugs tomorrow. CEL did come on(43) on ther way home from work.

 

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Clean it with electronic spray cleaner rather than carb cleaner. Test the plug to the computer.

 

x2 Do not use carb cleaner on the sensor element. Carb cleaner does not fully evaporate and it will leave behind oils that can damage the sensor. Not that cleaning it with electrical parts cleaner will really do anything ether. Anything that is on there is completely baked on and would require extreme heat to clean it.

Sure you can clean carbon or oil deposits off the metal exterior of the sensor. That doesn't clean the inside or business end (zirconia ceramic element) of the sensor.

 

code 43 doesn't necessarily mean the oxygen sensor is bad...it means that the oxygen sensor circuit is sensing something is abnormal. This could be fuel filter is clogged, fuel pressure regulator is bad it could even be the oxygen sensor connector is clogged up with dirt or debris. The oxygen sensor senses the oxygen content in the exhaust and compares that to the oxygen content in the air by using the side of the oxygen sensor connector. You should first check and see if that is dirty. If not, I would get a fuel pressure tester from Harbor Freight for $20. It has the correct piece to fit onto the fuel rail. Remember to use teflon tape on the threads so it doesn't leak fuel when you attach the leads and to the fuel rail bolt. Then test the fuel pressure. It should be above 30psi at idle(up to 37 at idle) then go up to 37(up to 47) when you fully open the throttle. If it's not within specs then you should first replace the fuel filter then recheck. If still not within specs you can replace the fuel pressure regulator. You can actually first take off the vacuum hose and smell it. If it smells like gas it's leaking and the fuel pressure regulator needs to be replaced. If all that checks out good then we gotta come up with another plan lol

 

Cleaned the 02 sensor and it did have a lot of oil on the connector/plug. Unfortunately it did not fix anything. I think the Sparkplugs look ok. I did take a picture. If I can get my oldest daughter to come over tomorrow I will post a pic of the plug(besides being a poor mechanic , I am computer illiterate). Before I buy a fuel pressure tester I have a couple of questions and/orstatements.
1. If it is a fuel issue, why doesnt it happen off
the bat? when the car is cold I dont haven a problem. It only starts after 2 miles or so. when it does start missing,sputtering I have to gun the engine to keep it going and get mild whiplash in the process.
2.Its manual so I can put it in neutral and when I rev the engine, it sounds/feels normal but when I put it back in gear I still have the same problem.
3. Would disconnecting the 02 sensor and driving it a couple of miles(would it still run?) to see what happens tell me anything or would this cause serious damage?
4. Forgot to mention the plugs did have a little oil on them. I had changed the valve cover gasket and seals/o rings and thougth I had that problem solved but obviously i didnt. I am leaking from the distributor cap(I have read the sticky on replacing the inner 0 ring but I am afraid I would screw it up) but dont how that is getting to my 02 and I dont see any other leaks.
Thanks

 

Like I said in my previous post if you have oil blocking the outside piece of the oxygen sensor it could cause the issues you are experiencing.

Yes, you can unplug the oxygen sensor and drive the car and if the oxygen sensor is the issue the issue should subside. Obviously the car will throw the oxygen sensor code.

It could very well be that oil leak that is causing the problems you are experiencing. The ecu doesn't start using the oxygen sensor until it has fully heated up, but it doesn't take very long for it to heat up.

It could also be the fact that oil is being slung around your distributor. It would be best to get a used distributor because oil can damage the ignitor. I would suggest first getting a used distributor from the junkyard and seeing if that helps considering that you wish not to do any major mechanical work on the distributor assembly itself. If the oil isn't causing a problem already it will cause a problem in the immediate future. Liquid, namely oil in this case, causes problems with electrical systems in general.

Make sure to make a mark with a sharpie in some place where the distributor meets the cylinder head. Then transfer the spot on the distributor with the same spot on the used distributor. Just choose a spot where you can use a ruler to measure the distance so you can be exact on the transfer of the mark. You will need to line up the spots when you put the used distributor on your engine so that you don't need to redo the ignition timing. Make sure you get a distributor from a '92 or '93 car. You should be able to note that your distributor cap will be different from a '90 or '91 car because the distributor cap will be different.

 

OK. Disconnected the 02 sensor and the car seems to be running better. No longer gettting a strong exhaust smell(failed to mention that previously) Of course I am getting a code 41 but no longer getting code 43. I will drive it a couple days to see if it will come on. If I dont get code 43, and the car runs good, does this rule out the fuel system as the problem and point to my oil leak on the 02 as the culprit? if I get any money back from Uncle Sam I will go ahead and get a new dizzy. I am afraid with a used one the seals will be hardenned and will have the same problem(yes/no?) How long can I drive the car without the 02 functioning? Thanks

 

If you like your catalyst, try not to drive too long without it.

Currently the ECU has no reference for actual A/F mixture so it is most likely just pulling fuel trim from the pre-programed tables in the ECU. It can fine tune these to a degree with the TPS, MAP, and temp sensors, but it does not know what the exhaust output of the engine is.

 

I love my catalyst! lol. I guess I better not fart around with the oil leak. Think Autozone is gonna give me a 4th 02 sensor for free? Me thinks not!

 

Ok, since you said you had a strong exhaust smell, I think you should check for an exhaust leak. Do you know how to seafoam your car ? If you do, you need to check for a faint exhaust leak....eg white smoke...while seafoaming your car from the exhaust manifold down just past the oxygen sensor. If you do not know how to seafoam your car, take it to a performance shop that knows how and ask them to seafoam it and check for an exhaust leak while they're doing that. Seafoaming can be pretty dangerous on an engine because it's imperative that the car does not stall out while you are doing it or it could hydrolock the engine.

An exhaust leak can cause the issues you are experiencing as the oxygen sensor senses oxygen that is coming in from the outside and dumps fuel into the engine thinking that the engine is not burning off the oxygen it thinks it coming from the combustion process...but is really coming from the outside air.

 

It's fairly easy to replace the internal seal. You just need to read the sticky in the faq's at the top of this subforum and take your time. The seal can be picked up on ebay and you can get the internal seal and external oring as a set from a lot of sellers.

 

I have done it on my 87 F150. I used a vaccumn line to the brake booster. I assume I could do the same thing on my Honda? Also on my truck I was unsure of how much of the seafoam to use so I only used a little bit(white smoke spooked me) and put the majority in the gas tank. Just enough to check for leak? I guess it would be best to have another person. One on the gas to prevent stalling and the other looking. I will take another look in the sticky about the internal o-ring. Thanks

 

You need enough to check for the leak...just use the whole can..it's a cheap way to find the leak without paying someone to use a smoke machine. Yes, one will seafoam while the other simultanously checks for the exhaust leak...you will see the white smoke coming out from somewhere along the exhaust manifold to cylinder head..exhaust manifold...exhaust manifold/exhaust pipe gasket..or downpipe

If you have a leak, you will need to repair the leak, then replace yet again the oxygen sensor since it will probably be fouled.

 

Thanks. I will do it this weekend. Hoping I dont have a leak. Thinking the oil leak is a much easier fix than an exhaust issue. Embarrassed about asking Autozone for another 02 sensor. If they say no. I dont think I will argue since it is really my fault the 02 is failing.

 

Just buy from rockauto...only get a denso oxygen sensor..remember to google search for coupon code before buying

 

Finally changed the internal seal on the distributor. Also ran seafoam to check for a exhaust leak. I need a new muffler but thankfully no leak before the O2 sensor. Cleaned the 02 connector once again. Going to drive the car for a week just to see if oil is still getting on the 02 connector and if not, I will change the 02 sensor. Thanks for everybodys help!

 

Finally put another Denso 02 on the car. No bogging/stalling but I still get code 43 once the car gets up to operating temp. have not checked fuel pressure. Was wondering if the main relay could be at fault? I know main relay problems usuallyl cause difficult starts or no starts, but just wondering.thanks

 

check your spark plugs and see if any of them is a different color...also they should all be tan...check if they are all black..

you need to do a fuel pressure test now ...if you have a harbor freight nearby they have a 20 dollar kit that works great

 

Ok. Iwill. Thanks