Slight miss caused by MAC Hpipe and Flowmasters?

rich5150 · 05-06-2003

I have been experiencing a slight "miss" or hesitation throughout the entire RPM range. I have taken the car back to STOCK as much as I can. The only thing I have on the car is a MAC H PIPE(no cats) and the Flowmaster exaust and I am still experiencing the problem. Is there anyway that putting on this H Pipe with NO CATS could be causing this miss? I have MIL eliminators on...so there are no codes that the engine is throwing...and the dealership says that the car 's computer is returning all good marks as far as their specs go.....

I have changed my fuel filter..... I have a good air filter (K&N)...clean MAF sensor. Could Mis-functioning O2 sensors cause this? I have run a bunch of tank fulls of 110 octane and 104 at times.....could this plug up my O2's and cause the engine to run rough..but throw no codes?

Does ANYONE HAVE ANY IDEAS at all....what could be causing this? I have been battling this for 6 months...and any help or suggestion would be appreciated.

Thanks much

Rich

drunkenfarmer · 05-06-2003

a freind of mine has a mac off raod h pipe in his car and welded in flow's and he is experiencing the problems, his was found in the throttle position sensor, maybe you have dirty injectors, there is a possibility your car is running rich due to the h pipe and your timing being too low for the 104 octane

Mana4Real · 05-06-2003

Was the 110 and 104 octane leaded gas? If it was, you need to replace your O2 sensors... It will clog them.

rich5150 · 05-06-2003

The 104 stuff was just the ADD in stuff.. but the 110 was in fact LEADED GAS. Would the O2's cause the car to miss like this? Thanks.

What about the throttle position Sensor? Is it ok to just SLAP in on...and screw it down...or is there some sort of adjustment to be made?

Mana4Real · 05-06-2003

A tps must be adjusted properly. But it's not very difficult with the proper instructions. Leaded gas will mess up the O2 sensors, It will cause it to run rough, not idle properly, poor gas mileage... I can keep going on, but I think you get the picture.

blue65636563 · 05-06-2003

Does the problem persist for the whole time your driving or is it just acting like that the first couple miles, upon first startup?

Adam

rich5150 · 05-06-2003

Hey guys!!
Thanks for all the INPUT. I ended up putting the TPS sensor on correctly...by loostening the screws and hand adjusting to get the thing seated right.. I now have no miss and a MUCH BETTER throttle response.

Thanks for everyones thoughts.