wont rev past 4000rpm in gear

[fznx]

Hey everyone just wondering my car wont rev past 4000 rpm in gear, ive tried switching to active select and still bombs out also tried power mode with no luck. The gear changes themselfs feel smooth and there is no clunking changing gears just the rpm hold, ove tried to look around and replaced the fuel filter with no luck, any advice will be appreciated

 

[Sabbath']

Sounds like the car has forced itself into a kind of limp home mode. I would get the computer checked for codes. Both the engine and transmission.

Sent from my GT-I9300 using Tapatalk

 

[XioiX1983]

I had a very similar problem, where it would hesitate at 4500 at then it would drop into the nextgear. It ended up being collapsed cats. Though the only way to really find out was to have them cut out. Cause the 5.7 does not have post cat 02 sensors.

 

[99notout]

If air is coming in, then combustion has to go out… Check the cats Especially if it just feels like it hits a wall and won't go past it.

 

[morphix]

Hey everyone just wondering my car wont rev past 4000 rpm in gear, ive tried switching to active select and still bombs out also tried power mode with no luck. The gear changes themselfs feel smooth and there is no clunking changing gears just the rpm hold, ove tried to look around and replaced the fuel filter with no luck, any advice will be appreciated

To test exhaust restriction (blocked cats, etc) you could try taking out your front o2 sensors.. I'm about to do this same test on my own car (v6 alloytec)

Sent from my Galaxy Nexus using Tapatalk

 

[fznx]

i disconnected the first 2 oxy sensors i could see, i had my ecu tool connected, before the test it would cap to 4000 and wouldnt budge over, with it disconnected it would go to 4100 haha not sure if that means it is cats. im getting a couple error codes, ive tried looking them up but i dont really get much in terms of what is affected. p2008, p0013, p0023, p0368. p0393, p0327.

 

[morphix]

i disconnected the first 2 oxy sensors i could see, i had my ecu tool connected, before the test it would cap to 4000 and wouldnt budge over, with it disconnected it would go to 4100 haha not sure if that means it is cats. im getting a couple error codes, ive tried looking them up but i dont really get much in terms of what is affected. p2008, p0013, p0023, p0368. p0393, p0327.

Were these oxygen sensors before your cats? Also when testing were you driving or just in driveway? Revs will limit at 4k if in neutral, etc.

 

[fznx]

yeah they were before the cats, im not sure i think there may be 2 cats on each pipe but not 100% not familliar with alloytec, nah went for a drive, made sure to check because i know about the 4k park/neutral limit

 

[XioiX1983]

I think the vz alloytch has 4 O2 sensors. The rear sensor is the one that checks the flow of the cats.

 

[morphix]

I think the vz alloytch has 4 O2 sensors. The rear sensor is the one that checks the flow of the cats.

That depends. Alloytech 175 has 2, only pre-cat. Alloytech 172kw has 4 alike the 190 to conform to euro 3 emissions iirc. Alloytech 190kw has 4, 2 pre and 2 post cat. Pre-cat is used to check fuel/air ratio and can impact performance. Post-cat is only to monitor cat efficiency.

However if the cat or muffler is blocked then its going to affect performance.

Sent from my Galaxy Nexus using Tapatalk