about a month ago i spent 2200 on car repair from anti freeze leaking into my head gaskets .. had to get two of them changed,water pump,and a full oil change.. and this was after changing the crankshaft position senor, sparkplugs and battery within two months before that.. now last week my check engine light goes on and comes up o2 sensor or catalytic converter.. very upset over this and does not want to buy another nissan after this.. scary how many other people have the same problems across America u would think Nissan would see this and improve there cars...

I just bought this car and have already had many problems with it. I should have known better than to trust the dealer I got it from. Their shop was trashy and ran down and looked like they just thru things together my car even had an old battery off another older model car than mine. I am almost certain my problem is with the exhaust system. I already replaced the manifold catalytic converter and that has not solved the problem. The exhaust leak it had before around the gasket has gotton worse and the car still seems to bog down when you drive it. I hope that the faulty cat has not already blown sh*t back into the engine and ruined it. The car wouldnt run at all or if it did it would run very sh*tty if that happened tho correct? I hate that I chose this car now. I was going to look at another one with less miles a week later but I didn't want to wait. Now Im stuck not able to drive my car until I get it fixed!!!!

I feel somewhat lucky in that this badly designed and faulty pre-cat and catalyst has not ruined my engine, YET, and that is only so far as I know. I did have the recall work done in 7-04, forgot about it. A few months ago I had the CES light appear, car care clinic made it go away. Then it returned. I then started having problems with a rough idle, hard to start, this was intermittent and infrequent until 3-25-09. Took to dealer on 3-26-09, They "found codes P0835 and P0725 for crank sensor and found oil in cam sensor and crank sensor, removed and replaced cam sensor and crank sensor." ($296.46). They also made note that I needed brake pads, running on 10%, and had an a/c hose leak. So very next morning I crank up and there is the CES light and very rough idle. They did not fix the problem. So I go to my mechanic and have the brake pads put on, a tire with a slow leak plugged ($212.88) and they were going to need order the a/c hose, from Nissan, same dealership I was about to return to to demand they fix the problem I'd just paid almost three hundred dollars for them to fix. So I just bought the a/c hose ($97.19) while I was there, saving myself $7 freight!

Back to dealership on 3-31-09, with the CES on again. This time they found codes for "cyl 3 misfire & plugs coil faulty codes for 02 sensor & catalyst leak & 2 02 sensor faulty" They told me I needed to fix the catalyst or the engine would suck the material into my engine and ruin it, had one in the shop for that reason at that moment!! I needed to prepay for the parts not in stock, a manifold exhaust $519.97, gasket exhaust, $18.59 and a bolt $10.91) Total $587.93 with estimated total parts and labor well over $1500.00. I was very worried, so I order the parts, but overnight changed my mind and went back and demanded they un-order the part and refund my $587.93, they did, with some complications with the actual invoice ticket/clerical inexperience of this ever happening. Got rude attitudes at this point. This particular dealership sits you in front of a beautiful big screen tv and has some young ladies that really don't tell you much, seem to demean you and talk down to you, and acted mad at me!! They whisk your car away where you can't see it and talk to the "tech" doing the repair work. I DISLIKE them to say the least. April 1, 2009, refund on the -$587.93, no fooling.

4-6-09, back to my mechanic, who put the new a/c hose on, serviced a/c, replaced 4 spark plugs and ran scanners to try and figure out why the devil it's still showing CES light on. Got codes for 02 sensor, had to order it. ($225.91)

Early morning 4-7-09, back to my mechanic who replaced the 02 sensor. But then the darn RPMs were just jumping up and down, fluctuating at an idle and driving. Mechanic worked on this from 8 until 12:30 and only charged $25 labor, very frustrated with not being able to figure it out and fix it. ($158.36) They sent me back to dealership to clear the codes.

Same afternoon 4-7-09, rude Jennifer tells me her tech is doing a transmission and can't do it, AND that by putting an "aftermarket" 02 sensor in, this could be causing the problems. She makes me an appt for the next morning at 7, they will shuttle me to work as I've already missed 3 days with this crap. I didn't call her to cancel, I hope she waited on me!!

I leave almost in tears, drive over to my same Car Care Clinic who comes up with a ton of codes. P1122 Manufacture control fuel & air metering, P2135 throttle pedal position sensor, switch A & B, voltage correlation, P0122 Throttle pedal position sensor low input, P0123 Throttle pedal position sensor high input, P0223 switch B circuit high, P0507 Idle air control system, and another RPM something high something relapse?? I got to scribbling this down there was so much, had my mechanic on the phone, he said have them clear the codes and take it to the dealership again. I'm really about to cry now. But the codes are cleared, CES is off, car is throttling up and down like crazy and I decide to drive across town and try the OTHER dealership. Nice guy. Allen, helped me out, got the throttling thing fixed, for the standard ($94.16) diagnostic charge, and also got the catalyst code again, which btw, wasn't showing at the Car Care Clinic. We talked; he and the tech gave me an estimate of $949.51 including tax, give or take a bolt or two to replace the faulty exhaust system.

At this point, I am out $1084.96. Car seems fine, CES light is off, but I am driving in fear of my engine sucking some of that pre-cat or catalyst material up into my engine and then . . . ??? new engine, buy excessive oil forever, deal with these people more and more, more codes and more sensors going crazy and having to be replaced at over a $100.00 a pop?

Nope. I think not. I've about decided I'm yanking that nasty faulty design pre-cat and catalyst out. I just haven't decided if I'll pollute the environment or replace it with an aftermarket exhaust system.

What do you guys think?? Anyone with aftermarket exhaust systems on these 2.5L Altimas?

It's incredible the number of people with these cars with this problem. I'm going to stay close to reality and not even worry about Nissan reimbursing me for their mess. But I'll NEVER buy another one. And I won't recommend a Nissan to any family, friend, foe or stranger. And a class actions suit I'd LOVE to be a part of that!!