# Codes - MAF, EGR and Knock



## 95maxstepdad (Jun 26, 2009)

The motor knocks on the lightest throttle openings. 

The engine almost dies after sitting in gear at a redlight for more than 30 seconds. 
The only cracked vacuum hose I could find was actually only a vent hose to the front valve cover. 

No signs of vacuum leaks from what I could see - The PCV hose looks intact.


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## DimaK (Sep 16, 2009)

welcome to the club
i got the same codes.make sure that the 2 bigger hoses are connected to the air box...


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## 95maxstepdad (Jun 26, 2009)

They are connected but old and showing signs of cracking. But I would have thought since they don't carry vacuum, they would not trigger a code. I guess I will try to replace them.


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## 95maxstepdad (Jun 26, 2009)

I think the resonator [RESONATOR]RESONATOR ASSY - Maxima (A32B) 1995 :: Nissan Parts, NISMO and Nissan Accessories - Courtesyparts.com ASSY - Maxima (A32B) 1995 :: Nissan Parts, NISMO and Nissan Accessories - Courtesyparts.com[/url]
assembly has a crack that is leaking air just past the MAF.

Anybody got one of these they want to sell (maybe bc you went with a CAI) for a 95 max?

*edit*
I guess even a CAI would probably reuse the same resonator assembly since its after the maf :/


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## JNCoRacer (Apr 18, 2003)

Most CAI's will have a mid-pipe section that replaces the resonator box, unless they use it and make a hybrid set-up.

Yes, having a leak AFTER the MAF will most likely cause problems as its getting more air than the MAF is registering, so its harder for the ECU to compensate.


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## JNCoRacer (Apr 18, 2003)

I had an extra one but I accidentally stepped on it in my garage a while back and broke off the piece that the crank case ventilation tube attaches to. 

You may want to check out some local junk yards. Most the time thats something they would just toss as its not a particularly valuable or sought after piece, like the engine or MAF themselves.


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## 95maxstepdad (Jun 26, 2009)

All the local salvage yards don't have one. ONe place said they have one for a 97 but they said their 'book' says 95-96 and 97-99s are different. I was gonna check there. But really, maybe the way to fix this is just go with a CAI and be done with it. Anybody got one of those for 50 or so?

hmmm.

1995 1996 1997 1998 1999 MAXIMA V6 3.5L COLD AIR INTAKE:eBay Motors (item 360175235851 end time Sep-26-09 20:24:45 PDT)

1995-1999 NISSAN MAXIMA COLD AIR INTAKE FILTER GLE 1996:eBay Motors (item 360170446382 end time Oct-11-09 19:16:11 PDT)


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## JNCoRacer (Apr 18, 2003)

The resonators are the same, its the "ram-air" scoop and filter box thats different between the years. 95-96 has the air temp sensor in the filter box lid, while 97-99 has it mounted in the scoop.


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## 95maxstepdad (Jun 26, 2009)

I guess I will try for the 97 one. Sounds like it might work. Thanks


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## 95maxstepdad (Jun 26, 2009)

Screw the local wrecking yards ( and the houston ones too). Nobody seems to want to mess with this enough to call me back and confirm they have it. I just ordered it new from courtesyparts.com

Looks like it should be here by maybe monday or tues at the latest and be about 125$ with shipping. The ONE place in houston that said they even had it wanted 75$ and they would not bother to ship it to me.

Thanks for your help *JNCoRacer* - next time Im in big D I might drop you a note. Beers on me - I will let you drive my Daily Driver - a BMW335 (with a little boost work)


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## JNCoRacer (Apr 18, 2003)

No problem. I wish the part I had was in better condition for you.

And you ordered it from Courtesy huh? If I had known that I couldve gotten it cheaper. Our car club here gets a discount on parts from them...like almost 20% on most stuff.

Are you in Houston? Me and a few of the Dallas guys are planning to go down there on OCtober 24th for a Maxima BBQ meet.


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## 95maxstepdad (Jun 26, 2009)

JNCoRacer said:


> And you ordered it from Courtesy huh? If I had known that I couldve gotten it cheaper. Our car club here gets a discount on parts from them...like almost 20% on most stuff.
> 
> Are you in Houston? Me and a few of the Dallas guys are planning to go down there on OCtober 24th for a Maxima BBQ meet.


Figures on the discount. Maybe I can call and get that taken off. Is there a secret word you have to give ??? 

*edit*
I just called and they said the price they gave me off the web site was as low as they could go. But thanks anyway. 

I am actually in college station. Most of the wifes (and the car is my stepsons), fam is there. I might be up for a trip around that date.


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## JNCoRacer (Apr 18, 2003)

Well at least you'll have youre new part and itll be one less hassle to deal with.

Keep us updated on the car status when you get the resonator installed.


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## 95maxstepdad (Jun 26, 2009)

Yeah, I got the complete duct assembly from the MAF to the throttlebody - just about all rubber parts should be new. That should eliminate all possible vacuum issues. If its still got trouble Im just about tempted to let the dealer handle it. I think it will at least be drivable to get it there if need be.


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## 95maxstepdad (Jun 26, 2009)

*strange sputtering and jerking after resonator replacement*

I replaced all parts between MAF and Throttle body. It started right up. But would stumble when you gave it gas in park. When put in gear it would die. 
After a dozen or so restarts I could get it to take gas VERY lightly and get it moving. Once it got rolling it would generally drive ok.

After about 10 mins of this it all of a sudden cleared up and is driving normally. Clearing codes and watching now.


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## 95maxstepdad (Jun 26, 2009)

Short story - *motor dies when hood slammed. Moving the MAF/resonator back and fourth causes stumble. *

Series of events - I shut it off for about 1 hour with the batt cable disconnected. Restarted and it would die when put in gear. The motor had cooled off almost completely so I thought it might have something to do with not being fully warmed up. 
I restarted it with the plan of letting it idle for a bit to get warmer. After I put my tools away I closed the hood (not the soft way of taking it down to the safety latch and then pressing), I just dropped it about mid way - and the motor dies. 

I restart it and drop it again, and it ALMOST dies. I begin to grasp the resonator and it stumbles consistently. 

I continued to move the resonator back and forth and the idle kind of smoothed out. It would then take gas normally and could be put in gear/driven with no problem. I guess its an electrical connection or some sensor around the MAF.


The 083063-63025 screw in the bottom of this pic 165 Air Cleaner :: Fuel & Engine Control :: Genuine Nissan Parts :: Maxima Parts (A32B) 1995-1999 :: Nissan Parts, NISMO and Nissan Accessories - Courtesyparts.com is missing and allowing allowing the MAF resonator to move around more than it should - gonna try toget it secured.


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## JNCoRacer (Apr 18, 2003)

Maybe the MAF itself is bad. I have an extra one of those I can send you along with the plug.


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## 95maxstepdad (Jun 26, 2009)

Thanks for the offer. I might take you up on it. I went back out and tried to move things around (even jiggled the connector to the MAF) but idle was not affected. I'm gonna put a week or so of time on it and see if I can figure out more. At least I have an idea in what area it likey is.


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## JNCoRacer (Apr 18, 2003)

Are you getting a CEL for the MAF?


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## 95maxstepdad (Jun 26, 2009)

Well, the CE did not clear when I had the batt disconnected. So Im not sure what is triggering it. I will probably take it to the AutoZ today or thurs. I really just wanted to get it back into the hands of my stepson for now.


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## 95maxstepdad (Jun 26, 2009)

*Update*

Well, my stepson has been driving it for about 2+ days since I replaced the rubber parts between the MAF and TB. It has stumbled twice and died once. 

The codes were checked last night and they were *wiring* for MAF, EGR and IAT. That might have been logged when I got the strange symptoms right after replacing all those rubber parts. Cleared codes and gonna watch it for a few more days. 

Got a code scanner on the way that in theory (but you know ebay auctions - Professional SUPER CAN OBD2 OBD II Code Scanner /Reader:eBay Motors (item 310169422153 end time Sep-30-09 17:00:34 PDT)) will allow me to read live data. 

Still more investigation to do..


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## JNCoRacer (Apr 18, 2003)

I'm gonna say the stalling is going to be related to the MAF. If it was acting up when you'd shake the intake then most likely the thermistor is loose. Unfortunately the 4th gens dont have a MAF that you can just change out the thermistor. You have to replace the whole MAF.


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## 95maxstepdad (Jun 26, 2009)

So how much you think you want for the MAF? 
Can you PM me.


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## JNCoRacer (Apr 18, 2003)

......PM sent.


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## 95maxstepdad (Jun 26, 2009)

I checked the voltage in to the MAF while driving. Its about 12v idling and as you slowly accelerate it drops. I thought 5v was the upper limit and it normally starts at .5.


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## 95maxstepdad (Jun 26, 2009)

*Seems all cured - so far after Good through EGR and TB cleaning.*

Long story - I wanted to get the oil leak fixed from the Valvecover - So the guy who did the control arm replacement for 65$ said he would do both VCs for 145$. I mentioned to him about the stalling and when he had it apart for the VCs he did a clean on the EGR ( he said it was completely pluged). I have not got a look at it in the light but he also said he cleaned the MAF - I think he meant TB). 

I think he at least spent an extra hour on it on the cleaning and when I asked him what I owed him he just said 145. I gave him an extra 10 - if that fixes it I will buy a 12pack. 


He pulled the metal plate off the IC board cover for the MAF and just replaced the plastic outer cover - LEAVING THE plate OFF. Is this solution done for cooling??? 

hmm


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## JNCoRacer (Apr 18, 2003)

Hey thats an *awesome* deal for getting all that work done. I can see the EGR tube being completely clogged. That would probably explain the EGR code issue. Ive seen them get pretty nasty.
Not sure about the MAF deal though, but hey you'll have the other one tomorrow. I always keep an extra one myself just in case.
Keep us updated on how it does during the next few days.


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## 95maxstepdad (Jun 26, 2009)

I just drove it for about an hour and it ran flawless. Yep - next few days will be the acid test.

So far with the replacment of the MAF to TB duct work (135), the VC gasket and parts (215) and control arm (135+65 labor), I got about 550 in it on top of the 1200 we paid for it. The really strange thing is they had repair records for oil changes and, radiator and alt replacement but it seems like they did absolutly NO PM work. 

I think it really needs the brakes flushed and bled.


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## 95maxstepdad (Jun 26, 2009)

*Seems fixed - no probs for about 70miles and 4days*

Seems rock solid. I drove it about 20 mls monday night and my step son has been driving it since. No CE and seems to have good driveability. 

thanks for your help.


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## JNCoRacer (Apr 18, 2003)

No problem. I'm glad to hear all is well.

I ended up having a whole lot of problems with mine this week. 

I finally got around to replacing the valve cover gaskets and guide tube seals. _(Which I found the seal on cylinder 1 wasnt even on the valve cover, hence the oil flooded cylinder.)_
Found I had 3 bad injectors, which caused my multiple cylinder misfire codes. Replaced those today, along with new OEM plugs and new OEM Z31 fuel filter.
The car runs so much smoother now. No hesitation. Loads of power back. Even shifts better in my opinion.

Next up will be the lower control arms.


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## 95maxstepdad (Jun 26, 2009)

Things change rapidly in my world it seems 

Sat afternoon - car stalled on step son. Would not restart immediately. Ten mins later started ok. 

Checked codes (No CE light) and it had MAF and Knock sensor logged in Freeze frame data. Cleared codes and drove about 90 mins with no malfunction. Replaced the MAF and drove some more. 

Waiting again. 

I guess the knock sensor is next.


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## JNCoRacer (Apr 18, 2003)

The knock sensor wouldnt cause it to stall. And the code for it alone wont trigger the CEL to come on. 
When it stalled did it still have the original MAF on it or was it the one I sent you?


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## 95maxstepdad (Jun 26, 2009)

That was the original one. Replace it last night before about another 45 mins of driving.


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