My engine is running real rough, on all RPM. My check engine light is on, and the code readings I got were.

1. EGR needs replaced
2. Front right O2 sensor
3. Knock sensor


My quiestion is would any of these things make my car run as bad as it is. and even like smell flooded and stuff?? Sorry I would have searched my I don't have search function for some reason....


Thanks guys.

 

all those cold make the engine run rough. id get them replaced asap so you dont cause further problems. make sure your oil isnt low either, that could make it run rough as well

 

Yeah, I know it's not the oil. Just had a sythetic change done 1,000 miles ago and made sure the oil was good. The check engine like was acutally on for a couple days, i couldn't figure out how to check it cause it's a 95 but. Then as I was coming home last week it started running REALLY rough, i mean. It will stay running it is just REAL rough, almost hesitating not relaly missing.

and I also haven't tried to drive the car since the roughness started.

 

start by replacing O2 sensor. It might be the reason you're running rough and could be causing the KS code too.

 

What he said knock sensor sometimes gets thrown when other codes are thrown

 

It's running REALLLLLLY rough though, i mean. So rough I wouldn't think to drive it. You really think the o2 sensor could do that? I have had o2 sensors go bad in other types of cars, but they have never changed the way the car ran. It's like a real rough on idle, and on any rpm.

It also is hard to start, as well as seems like it floods when you start it. You can here the exhaust raddle.

 

It's probably the EGR valve leaking and causing a very rough idle.

Start by fixing the EGR system, clear the error codes and see what comes back. If the O2 and KS come back, fix the O2 first, then check to see if the KS comes back. If it does, replace that as well.

 

Great, thanks a lot! I'll post how it goes, I will be getting the parts tomorrow. Not gettin the KS actually will save me some money.

 

Ok, so... I have been waiting for it to warm up a bit to do anything on this but. Now, the car will run fine for a little while, then it will go back to running rough. It's complety inconsistant. I reset my ECU and the light hasn't came back yet but. Like i said, it will run rough like that for a little while, then all of a sudden it will be running ok. I mean, it still don't run like it should, but there isn't a power loss or anything. It keeps going back and forth, one min power loss and stumble, next min just a slight bit of stumble with no power loss.

I was going to go ahead and do the o2 sensor first since it's teh easist but, do you guys thing the problem still is in teh codes it gave me the first time? Could it be something else? Like a wire loose? Somthing need cleaned? Suggestions?


Thanks.

 

As you stated you reset the codes just drive about 100 miles and most likely the codes will pop back up so I would wait till they came back if you really dont want to spend the money this second but if you did I would start with the O2 sensor

 

O2 will not cause a rough running engine, a leaky EGR WILL!

Replace or fix the EGR issue first, it very well could be causing your o2 error as well because the engine isn't running correctly.

 

From what I have read the o2 sensor will make your car run rough. What what i understand when it goes bad it change change your timing. If that does happen that would also make your car run rough, loose power, and such... is this not true?

 

I had a similar problem... only got better after the following; 2 oxygen sensors, knock sensor, and I had 2 bad ignition coils (though no codes showed for these right away). Shop for a good price.. Oxygen sensors can be about $70 on line, can find them for around 60... knock sensor cheaper on line about $100, got mine at Autozone & got hosed

 

Assist with oxygen sensors ...

> The code reader reports two codes. P0159 02 sensor CKT slow response (bank 2, sensor 2), P0158 02 sensor circuit high volts (bank 2, sensor 2). Can someone share where this bank 2, sensor 2 02 is located, and whether it is easy to change or require special tools/techniques/know-how?

[I actually have a 3rd code, P0325 knock sensor 1 circuit malfunction, though given the advice provided earlier, will replace the 02 first.]

> My local dealership sells the 02 for $145. Does anyone know what the OEM brand/model is and if it matters if I go with another brand like Bosch or Denso? Also, any advice on where to get good quality 02 sensors online for a reasonable price?

Thanks.