Clogged cats?
Thread Starter
TECH Addict
Joined: Nov 2005
Posts: 2,379
Likes: 2
Clogged cats? This sounds more accurate of a description.
Short of it is that my MAF was dirty, I tuned it while it was dirty and probably threw lots of fuel through the system. Only touched the MAF tuning this morning, now I regret messing with it.
Symptoms include
-sluggish under 2200rpm
-car feels slower at WOT and acceleration in general
-popping out the exhaust
-thump/popping ie you'd think cork pop but deeper in bass
Things tested
-original and slightly modded tunes still show same symptoms
-once MAF was cleaned, adjustments made by the computer to fuel trims were HALF of what they read, instead of dumping 20% more it was 10%...
-Car doesn't break loose tires in 1st as easily, chirps 2nd, but felt... weird... slow...
Short of it is that my MAF was dirty, I tuned it while it was dirty and probably threw lots of fuel through the system. Only touched the MAF tuning this morning, now I regret messing with it.
Symptoms include
-sluggish under 2200rpm
-car feels slower at WOT and acceleration in general
-popping out the exhaust
-thump/popping ie you'd think cork pop but deeper in bass
Things tested
-original and slightly modded tunes still show same symptoms
-once MAF was cleaned, adjustments made by the computer to fuel trims were HALF of what they read, instead of dumping 20% more it was 10%...
-Car doesn't break loose tires in 1st as easily, chirps 2nd, but felt... weird... slow...
They sell backpressure testers through most of the major tool companies snap on,matco,mac etc which plugs in where the o2 sensor does and it has a gauge that will tell you if there clogged or just disconnect your exhaust and see if its better. If it sounds like its snap crackle and popping with a light pinging under load I would say its clogged its one of those sounds you just learn from hearing it enough times. It also shouldnt rev past 3500-4000 if the cat is clogged.
Thread Starter
TECH Addict
Joined: Nov 2005
Posts: 2,379
Likes: 2
I figured it out, number 4 spark plug wire burnt up, misfire, raw fuel going through hence the popping which sounded like coming from the passenger side along with the thumping. Passenger side exhaust pipe had more of a raw fuel smell too and when I went to look in the engine bay, smelled something burning...
