# 1996 Altima - Need urgent help



## goofy123 (Jun 10, 2007)

Friends,

I initially had a P1400 code after lot of testing (which all checked out fine) I assumed it to be a mechanical diaphragm failure inside the EGR solenoid and replace the solenoid. Have driven more than 400 miles and still the EGR system is showing "not ready" but no P1400 code. Meanwhile I am getting P0420 code, for catalytic converter, the exhaust does not smell and the acceleration is good. I do experience a rough idle but the idle is steady at @ 650 rpm- 700rpm will rise higher to @ 850 rpm when the AC compressor or radiator fan comes on. The previous owner stated they had replaced the front O2 sensor, so what could be the problem. The last time I checked the plugs the seemed little while, but that must be due to the EGR malfunctioning leading to the engine running hot.

Anything I need to check before replacing CC. I need to pass emission this week

Thanks in advance........


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## Asleep (Jan 19, 2003)

check the hose that goes into the bottom of the egr. every nissan ive worked on has had a mushy hose going into it. the hose should be firm and not mushy feeling.


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## goofy123 (Jun 10, 2007)

Thanks for your prompt reply, which hose do you mean the EGR valve sits directly on the intake and there are no hoses from the bottom. Only BPT has hose from the bottom connected to the exhaust. I have replaced all vacuum hoses and bottom hose from BPT valve a week back.


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## Asleep (Jan 19, 2003)

there should be a hose going from the bpt to the egr valve. maybe even 2 of them. 
while youre in that area, check all of the egr system hoses.


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## goofy123 (Jun 10, 2007)

I have replaced all vacuum hoses including the ones going to EGR valve but my main problem is regarding rough idle and P0420 code.


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## Asleep (Jan 19, 2003)

does the egr work like its supposed to?
have you checked your intake manifold for leaks?


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## goofy123 (Jun 10, 2007)

EGR valve works fine, I haven't checked intake manifold, but if there were a leak I should notice extensive blistering on my spark plug and also higher rpm. None of which I have noticed so if there were a leak it should be minor. Correct me if I am wrong here. Any other symptoms of intake leaks?


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## Asleep (Jan 19, 2003)

bad idle, erratic idle, driveability issues...
did you try spraying liquids on the manifold while its running?


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## goofy123 (Jun 10, 2007)

Will try and spray carb cleaner around intake in the evening..... no driveability issues.... just rough idle i should say....can maintain 70mph at 2400 rpm..... all gear shift smoothly @ 3200 rpm....


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## goofy123 (Jun 10, 2007)

Sprayed a whole can of Carb cleaner all along the inlet, but could not get it around the bottom of the inlet manifold. There was no change in the idling, any new suggestions......


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## goofy123 (Jun 10, 2007)

One interesting thing noticed today, put the ECM in test mode-II to check for front O2 sensor which seemed okay and when got it back to Test mode-I the check engine light was gone, I scanned with the generic scan tool and found the ECM to have reset itself (expected). But after resetting itself the idle seemed a lot smoother, so is there any reason that ECM is modulating the Fuel ratio after detecting a fault which is leading to less than smooth idling. As I mentioned in my earlier diagnosis I haven't found any leaks on the inlet side. Any views on this is highly welcomed


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## LONDONDERRY (May 19, 2004)

I'd like to chime in on this one.
Most of the erratic idle issues seem to be from either the car needing a good tune up. EGR valve issues or intake manifold issues. I would recheck all of these issues again


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