Ok...let me start off by saying I've searched around here, and locally, for my answer...with no success.

Here's the rundown...2 weeks ago I had a CEL on for 3 codes...
1. knock sensor
2. oxygen sensor
3. vehicle speed sensor

I've been having bogging issues since the codes were shown. No mechanic would give me a decent explanation without wanting $100. So...I figured I would source out all the possible causes before I pay a diag fee.

Last week I seafoamed the car through the brake booster, took my MagnaFlow HFC off (because I've heard its possible they go out prematurely...plus to source out the oxygen sensor problem), then cleared the codes to see which ones would come back on as soon as the readiness monitors were set. Well, the light has stayed off since then and I checked to see if all 7 monitors were set. To my suprise, they were all set and no codes were shown. At this time, the bogging was no longer occurring.

Today (about an hour ago), I got off work and hopped on the interstate to open the throttle up. So I dropped to 3rd, eased into the throttle until I was flooring it. Everything ran smooth, I felt my MEVI activate and had no bog issues at all. After I shifted to 4th, my CEL started flashing...so I got off the nearest exit, checked my OBD...not only did I just have 1 code, but it was also NONE of the codes I had previously. I got a Cylinder 3 Misfire code.

So in conclusion, I then drove home and hopped on here just to post a long, dreaded out thread about my problems...IN HOPES that someone will explain to me what COULD be going on, without me having to pay them a diag fee lol.

Thanks in advanced!

 

Check cylinder #3, remove spark plug, replace with a new one and a new or used from the junkyard coil pack and you're done. Bogging be gone!


I wish my bogging problem was this simple

 

But what about the previous codes? Why did they show up and simply just go away for good after I cleared them? That's the main thing confusing me...could those codes just show up simply because a misfire? And could all 3 codes just go away after I removed the cat?

 

those first codes might not show up right away. but they will most likely be back. how long has it been that youre saying theyre gone for good?

sounds like you seafoamed and might have opened up a can of worms

 

Well, I expect the Vehicle speed sensor to show back up, because that has been a problem for about a year. But to answer your question, it has been about a week that they have been gone, and from my understanding...if all readiness monitors are complete (and my drive cycle is complete as well), the codes would've showed by now.

 

Check the spark plugs, when was the last time they were changed? If you can't remember it might be about that time. Also check the injector for that cylinder.

 

My 1 cylinder was misfiring and it ended up being the ignition coil. It was broken in half....

 

check your plugs and wires on that cyl. would be a good time for a general tune-up.

as for your other codes:

1. knock sensor is probably a piggy back code of the o2 sensor, mess with this last.
2. which o2 is it throwing the code for? this + your misfires could be causing bogging.
3. is your speedo working ok? what exactly does the code say?

 

deffinetly make sure your speedo is working ok, ive had the error code for mine almmost a year now but ive driven behind a buddy a few times and did the same speed as him (70mph) but my speedo said i was doing the correct speed, i just left it and havent had any problmes. it could just be the wire conection, but i dont have much experience with this problem except for what i just said, hope it helps.

 

Any updates on the issues? I'm curious as well.

 

if u need a knock sensor the cheapo ebay ones are just fine, at least for me no issues. Speed sensor is about 20-25bucks and u can get a o2 for about 40bucks now.

 

This is easy....... swap #1 & #3 coil packs and see if the problem transfers to the #3 cylinder! If not Swap #1 spark plug with #2 spark plug and wait to see if the problem transfers as well! This troubleshooting cost you nothing $$$$$ but time!

 

Sounds like a bad coil pack. Maybe a dirty MAF?

 

Update...I fixed the bog issues...took the spark plugs out and they were pretty nasty lol. Also changed the coil out cause my friend had used OEM coils for $20 each, couldn't turn that one down. Car runs perfect now, misfire code is gone, but the knock sensor code came back on (I will be taking care of it very soon).

Thanks for the help EVERYONE!

 

glad to hear everything worked out for you

word to the wise.....flashing CEL = misfire.

Im right down 840 (near mt. juliet) if you ever need any help

 

I had a misfire and it turned out to be a fuel injector... a little more pricey. I also had replaced spark plugs and coil packs before doing the injector. But I went through the same issues and troubleshooting as OP did

 

I agree with you about the injector. i was having HORRIBLE surging problems and was getting a Knock sensor, Misfire on #3 and occasionally a multiple misfire. the common problem is a coil pack or plug, but i replaced those and the problem kept getting worse. I took the fuel filter off and brown chunky gas poured out of the bottom. I filled up 4 tanks of 93 octane, changed fuel filter and seafoamed via BB 2 times. I also dumped octane booster and fuel injector cleaner into the tank( I think i had water in the gas)... the problem has become much better and gone away (Knock on wood lol)...

Bottom line- When Nissan tells you to use premium fuel, it's FOR A REASON.