2005 SE IDLE/EXHAUST ISSUES!

[416BRAND]

2005 Maxima SE
I've now been to two dealerships and 4 local mechanic shops. Nobody has a clue. Just keeps telling me different things. So some advice needed and a question for you

I noticed one of my flex pipes is a bit shreaded and could soon be a full out leak.
Is it ok to chop out the flex pipe thats shredded and just weld a new one in place like I did on my 4th gen? It looks a bit more complicated and $800+ for the entire section of piping seems a bit retarded. This isnt mine but its a picture of the section I'm talking about:

Could this cause random idle at normal operating temperatures?

When I'm parked after have been driving for 15-20 mins so at normal operating temp all of a sudden my idle just jumps to 1.5-2K for no reason. When idle at a light I'm getting rough slightly low idle and tons of vibration in the steering wheel and a dull bass like muffle sound plus when I accelerate sometimes I lose all gas pedal and the engine feels choked, cuts out, and the car either goes into limp mode or fixes itself once im in going above 40 or so.

Also when I rev up then watch the revs going down the needle lags and jerks down slowly. Its not smooth at all.

I have replaced:
- front right upstream o2 sensor by the firewall,
- spark plugs,
- throttle body,
- MAF,
- air filter,
- did a transmission flush.
- All other fluids are fine except I do have a small p/s leak (it was really bad even from the pressure switch/sensor on the high pressure hose which I replaced as well which fixed the leak when it was really bad. So now maybe from the pump or other part of the hose.
- I've done 2 idle relearns at the dealership as well

Happens way more frequently when it rains!

One dealership says it could be the ground wire. Sometimes I notice some flickering in the gauge cluster lighting. Dealership did say the batt voltage was a little jumpy or something to that affect. Could this really be the cause of all my problems? Why would that really only occur once the car has warmed up fully?

I've spent nearly $3600 now trying to fix this issue. Its extremely dangerous. HELP!
NO CEL CODES.

[Ilya]

Hi there.

I haven't had a Maxima in years and when I did it was two 4th gens...but you can clean the ground locations yourself. Just take the 10mm bolts off (most of them are 10mm) and take a wire brush to the small area and then reinstall.

However, is the MAF you got new? Don't know about the 6th gen but do these cars still have IACV's (Idle Air Control Valve)? Perhaps yours is on the fritz...on the 4th gen it was near the throttle body.

As for the exhaust, I don't see why not if you have a shop that knows how to do it. No need for a whole new pipe if they can install a new one.

[NutriaforBreakfast]

Try cleaning the idle air control valve first
could be carbon buildup
Also could be carbon in the throttle body interfering with the "butterfly"

[416BRAND]

UPDATE:

2005 SE.

Jumpy idle all of a sudden and no acceleration then car goes into limp mode. This happens more so at slow idle like speeds but it also did it to me going 80mph the other day on the highway.

I took the car to the dealership before and they replaced the Negative Ground Cable to the battery. The issue went away for 2 months. Now its back with a vengeance. AS SOON as the car gets to normal operating temperature. Its done. I can't even drive it for 15-20 minutes. I've been to SIX shops. 2 DEALERSHIPS. Nobody knows whats wrong.

What I have replaced with new parts mostly OEM:

- 2 Upstream NTK Oxygen O2 Sensors (Air/Fuel Ratio Sensors)
- Swapped Mass Air Flow from a Murano. No change.
- All new NTK Spark Plugs (coils seemed to have no signs of cracks either)
- Throttle Body (TPS is on it)
- PCV Valve
- Air Filter
- Oil changes always on time. But car burns Mobil 1 5w30 like crazy.
- Negative Ground Cable
- Right Rear Wheel Hub (originally though it could be ABS Speed Sensor there too but nope)
- Power Steering High Pressure hose (aftermarket POS) and OEM Pressure Sensor Switch (now I have that lovely little whine that most people get with the aftermarket hose lol)
- Did 2 idle relearns at the dealership too

I've done all of this to my car in 6 months. I just bought this car last Sept. I'm pretty ****ing pissed off. I've spent more than I paid for the car in repairs and rental cars since I bought it. I miss my 4th gens.

I saw someone mention they re-grounded the MAF. But I haven't tried that myself. But still. this only seems to happen soon as car gets hot.

Alternator ground wire strap or whatever I have asked the mechanic to look at and he says its good.

I have a crack in my exhaust where the downstream right side O2 sits. Giving me a code for that O2. Where that pre cat is. But that surely couldn't be the issue could it? Why would this cause limp mode. Unless that cat was totally clogged as well or something?

PLEASE. No codes are coming up other than the downstream O2 P1273 but I know thats because of the crack in the exhaust right beside it. Everyone says not to buy aftermarket Cats either because then it wont pass emissions. I'm in Toronto, Canada.

Could this be caused by a vaccuum leak maybe by the valve cover or intake gasket idk? Metal expands when hot yes so maybe its making a tiny crack soon as engine is hot causing vaccum leak somewhere? This could happen with old hoses too I'm assuming?